diff options
Diffstat (limited to 'fpga/usrp2/models/FIFO_GENERATOR_V4_3.v')
| -rw-r--r-- | fpga/usrp2/models/FIFO_GENERATOR_V4_3.v | 3494 |
1 files changed, 3494 insertions, 0 deletions
diff --git a/fpga/usrp2/models/FIFO_GENERATOR_V4_3.v b/fpga/usrp2/models/FIFO_GENERATOR_V4_3.v new file mode 100644 index 000000000..bcb9af8a7 --- /dev/null +++ b/fpga/usrp2/models/FIFO_GENERATOR_V4_3.v @@ -0,0 +1,3494 @@ +/* + * $RDCfile: $ $Revision: 1.1.2.15 $ $Date: 2007/07/25 15:58:33 $ + ******************************************************************************* + * + * FIFO Generator v3.3 - Verilog Behavioral Model + * + ******************************************************************************* + * + * Copyright(C) 2006 by Xilinx, Inc. All rights reserved. + * This text/file contains proprietary, confidential + * information of Xilinx, Inc., is distributed under + * license from Xilinx, Inc., and may be used, copied + * and/or disclosed only pursuant to the terms of a valid + * license agreement with Xilinx, Inc. Xilinx hereby + * grants you a license to use this text/file solely for + * design, simulation, implementation and creation of + * design files limited to Xilinx devices or technologies. + * Use with non-Xilinx devices or technologies is expressly + * prohibited and immediately terminates your license unless + * covered by a separate agreement. + * + * Xilinx is providing theis design, code, or information + * "as-is" solely for use in developing programs and + * solutions for Xilinx devices, with no obligation on the + * part of Xilinx to provide support. By providing this design, + * code, or information as one possible implementation of + * this feature, application or standard. Xilinx is making no + * representation that this implementation is free from any + * claims of infringement. You are responsible for obtaining + * any rights you may require for your implementation. + * Xilinx expressly disclaims any warranty whatsoever with + * respect to the adequacy of the implementation, including + * but not limited to any warranties or representations that this + * implementation is free from claims of infringement, implied + * warranties of merchantability or fitness for a particular + * purpose. + * + * Xilinx products are not intended for use in life support + * appliances, devices, or systems. Use in such applications is + * expressly prohibited. + * + * This copyright and support notice must be retained as part + * of this text at all times. (c)Copyright 1995-2006 Xilinx, Inc. + * All rights reserved. + * + ******************************************************************************* + * + * Filename: fifo_generator_v4_3_bhv.v + * + * Description: + * The verilog behavioral model for the FIFO generator core. + * + ******************************************************************************* + */ + +`timescale 1ps/1ps + +/******************************************************************************* + * Declaration of top-level module + ******************************************************************************/ +module FIFO_GENERATOR_V4_3 +( + BACKUP, + BACKUP_MARKER, + CLK, + DIN, + PROG_EMPTY_THRESH, + PROG_EMPTY_THRESH_ASSERT, + PROG_EMPTY_THRESH_NEGATE, + PROG_FULL_THRESH, + PROG_FULL_THRESH_ASSERT, + PROG_FULL_THRESH_NEGATE, + RD_CLK, + RD_EN, + RD_RST, + RST, + SRST, + WR_CLK, + WR_EN, + WR_RST, + INT_CLK, + + ALMOST_EMPTY, + ALMOST_FULL, + DATA_COUNT, + DOUT, + EMPTY, + FULL, + OVERFLOW, + PROG_EMPTY, + PROG_FULL, + RD_DATA_COUNT, + UNDERFLOW, + VALID, + WR_ACK, + WR_DATA_COUNT, + SBITERR, + DBITERR + ); + + /**************************************************************************** + * Definition of Ports + * + * + ***************************************************************************** + * Definition of Parameters + * + * + *****************************************************************************/ + + /**************************************************************************** + * Declare user parameters and their defaults + *****************************************************************************/ + parameter C_COMMON_CLOCK = 0; + parameter C_COUNT_TYPE = 0; + parameter C_DATA_COUNT_WIDTH = 2; + parameter C_DEFAULT_VALUE = ""; + parameter C_DIN_WIDTH = 8; + parameter C_DOUT_RST_VAL = ""; + parameter C_DOUT_WIDTH = 8; + parameter C_ENABLE_RLOCS = 0; + + parameter C_FAMILY = "virtex2"; + //Not allowed in Verilog model + + parameter C_HAS_ALMOST_EMPTY = 0; + parameter C_HAS_ALMOST_FULL = 0; + parameter C_HAS_BACKUP = 0; + parameter C_HAS_DATA_COUNT = 0; + parameter C_HAS_MEMINIT_FILE = 0; + parameter C_HAS_OVERFLOW = 0; + parameter C_HAS_RD_DATA_COUNT = 0; + parameter C_HAS_RD_RST = 0; + parameter C_HAS_RST = 0; + parameter C_HAS_SRST = 0; + parameter C_HAS_UNDERFLOW = 0; + parameter C_HAS_VALID = 0; + parameter C_HAS_WR_ACK = 0; + parameter C_HAS_WR_DATA_COUNT = 0; + parameter C_HAS_WR_RST = 0; + parameter C_IMPLEMENTATION_TYPE = 0; + parameter C_INIT_WR_PNTR_VAL = 0; + parameter C_MEMORY_TYPE = 1; + parameter C_MIF_FILE_NAME = ""; + parameter C_OPTIMIZATION_MODE = 0; + parameter C_OVERFLOW_LOW = 0; + parameter C_PRELOAD_LATENCY = 1; + parameter C_PRELOAD_REGS = 0; + parameter C_PRIM_FIFO_TYPE = 512; + parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0; + parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0; + parameter C_PROG_EMPTY_TYPE = 0; + parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0; + parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0; + parameter C_PROG_FULL_TYPE = 0; + parameter C_RD_DATA_COUNT_WIDTH = 2; + parameter C_RD_DEPTH = 256; + parameter C_RD_FREQ = 1; + parameter C_RD_PNTR_WIDTH = 8; + parameter C_UNDERFLOW_LOW = 0; + parameter C_USE_FIFO16_FLAGS = 0; + parameter C_VALID_LOW = 0; + parameter C_WR_ACK_LOW = 0; + parameter C_WR_DATA_COUNT_WIDTH = 2; + parameter C_WR_DEPTH = 256; + parameter C_WR_FREQ = 1; + parameter C_WR_PNTR_WIDTH = 8; + parameter C_WR_RESPONSE_LATENCY = 1; + parameter C_USE_ECC = 0; + parameter C_FULL_FLAGS_RST_VAL = 1; + parameter C_HAS_INT_CLK = 0; + parameter C_USE_EMBEDDED_REG = 0; + parameter C_USE_FWFT_DATA_COUNT = 0; + + //There are 2 Verilog behavioral models + // 0 = Synchronous FIFO/ShiftRam FIFO + // 1 = Asynchronous FIFO + parameter C_VERILOG_IMPL = (C_IMPLEMENTATION_TYPE==0 ? 0 : + (C_IMPLEMENTATION_TYPE==1 ? 0 : + (C_IMPLEMENTATION_TYPE==2 ? 1 : 0))); + + + /****************************************************************************** + * Declare Input and Output Ports + *****************************************************************************/ + input CLK; + input BACKUP; + input BACKUP_MARKER; + input [C_DIN_WIDTH-1:0] DIN; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE; + input RD_CLK; + input RD_EN; + input RD_RST; + input RST; + input SRST; + input WR_CLK; + input WR_EN; + input WR_RST; + input INT_CLK; + + output ALMOST_EMPTY; + output ALMOST_FULL; + output [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT; + output [C_DOUT_WIDTH-1:0] DOUT; + output EMPTY; + output FULL; + output OVERFLOW; + output PROG_EMPTY; + output PROG_FULL; + output VALID; + output [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT; + output UNDERFLOW; + output WR_ACK; + output [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT; + output SBITERR; + output DBITERR; + + + wire ALMOST_EMPTY; + wire ALMOST_FULL; + wire [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT; + wire [C_DOUT_WIDTH-1:0] DOUT; + wire EMPTY; + wire FULL; + wire OVERFLOW; + wire PROG_EMPTY; + wire PROG_FULL; + wire VALID; + wire [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT; + wire UNDERFLOW; + wire WR_ACK; + wire [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT; + + + wire RD_CLK_P0_IN; + wire RST_P0_IN; + wire RD_EN_FIFO_IN; + wire RD_EN_P0_IN; + + wire ALMOST_EMPTY_FIFO_OUT; + wire ALMOST_FULL_FIFO_OUT; + wire [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT_FIFO_OUT; + wire [C_DOUT_WIDTH-1:0] DOUT_FIFO_OUT; + wire EMPTY_FIFO_OUT; + wire FULL_FIFO_OUT; + wire OVERFLOW_FIFO_OUT; + wire PROG_EMPTY_FIFO_OUT; + wire PROG_FULL_FIFO_OUT; + wire VALID_FIFO_OUT; + wire [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT_FIFO_OUT; + wire UNDERFLOW_FIFO_OUT; + wire WR_ACK_FIFO_OUT; + wire [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT_FIFO_OUT; + + + //*************************************************************************** + // Internal Signals + // The core uses either the internal_ wires or the preload0_ wires depending + // on whether the core uses Preload0 or not. + // When using preload0, the internal signals connect the internal core to + // the preload logic, and the external core's interfaces are tied to the + // preload0 signals from the preload logic. + //*************************************************************************** + wire [C_DOUT_WIDTH-1:0] DATA_P0_OUT; + wire VALID_P0_OUT; + wire EMPTY_P0_OUT; + wire ALMOSTEMPTY_P0_OUT; + reg EMPTY_P0_OUT_Q; + reg ALMOSTEMPTY_P0_OUT_Q; + wire UNDERFLOW_P0_OUT; + wire RDEN_P0_OUT; + wire [C_DOUT_WIDTH-1:0] DATA_P0_IN; + wire EMPTY_P0_IN; + + assign SBITERR = 1'b0; + assign DBITERR = 1'b0; + +// choose the base FIFO implementation for simulation +generate +case (C_VERILOG_IMPL) +0 : begin : block1 + fifo_generator_v4_3_bhv_ver_ss + #( + C_COMMON_CLOCK, + C_COUNT_TYPE, + C_DATA_COUNT_WIDTH, + C_DEFAULT_VALUE, + C_DIN_WIDTH, + C_DOUT_RST_VAL, + C_DOUT_WIDTH, + C_ENABLE_RLOCS, + C_FAMILY,//Not allowed in Verilog model + C_HAS_ALMOST_EMPTY, + C_HAS_ALMOST_FULL, + C_HAS_BACKUP, + C_HAS_DATA_COUNT, + C_HAS_MEMINIT_FILE, + C_HAS_OVERFLOW, + C_HAS_RD_DATA_COUNT, + C_HAS_RD_RST, + C_HAS_RST, + C_HAS_SRST, + C_HAS_UNDERFLOW, + C_HAS_VALID, + C_HAS_WR_ACK, + C_HAS_WR_DATA_COUNT, + C_HAS_WR_RST, + C_IMPLEMENTATION_TYPE, + C_INIT_WR_PNTR_VAL, + C_MEMORY_TYPE, + C_MIF_FILE_NAME, + C_OPTIMIZATION_MODE, + C_OVERFLOW_LOW, + C_PRELOAD_LATENCY, + C_PRELOAD_REGS, + C_PROG_EMPTY_THRESH_ASSERT_VAL, + C_PROG_EMPTY_THRESH_NEGATE_VAL, + C_PROG_EMPTY_TYPE, + C_PROG_FULL_THRESH_ASSERT_VAL, + C_PROG_FULL_THRESH_NEGATE_VAL, + C_PROG_FULL_TYPE, + C_RD_DATA_COUNT_WIDTH, + C_RD_DEPTH, + C_RD_PNTR_WIDTH, + C_UNDERFLOW_LOW, + C_VALID_LOW, + C_WR_ACK_LOW, + C_WR_DATA_COUNT_WIDTH, + C_WR_DEPTH, + C_WR_PNTR_WIDTH, + C_WR_RESPONSE_LATENCY, + C_FULL_FLAGS_RST_VAL, + C_USE_EMBEDDED_REG + ) + gen_ss + ( + .CLK (CLK), + .RST (RST), + .SRST (SRST), + .DIN (DIN), + .WR_EN (WR_EN), + .RD_EN (RD_EN_FIFO_IN), + .PROG_EMPTY_THRESH (PROG_EMPTY_THRESH), + .PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT), + .PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE), + .PROG_FULL_THRESH (PROG_FULL_THRESH), + .PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT), + .PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE), + .DOUT (DOUT_FIFO_OUT), + .FULL (FULL_FIFO_OUT), + .ALMOST_FULL (ALMOST_FULL_FIFO_OUT), + .WR_ACK (WR_ACK_FIFO_OUT), + .OVERFLOW (OVERFLOW_FIFO_OUT), + .EMPTY (EMPTY_FIFO_OUT), + .ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT), + .VALID (VALID_FIFO_OUT), + .UNDERFLOW (UNDERFLOW_FIFO_OUT), + .DATA_COUNT (DATA_COUNT_FIFO_OUT), + .PROG_FULL (PROG_FULL_FIFO_OUT), + .PROG_EMPTY (PROG_EMPTY_FIFO_OUT) + ); +end +1 : begin : block1 + fifo_generator_v4_3_bhv_ver_as + #( + C_COMMON_CLOCK, + C_COUNT_TYPE, + C_DATA_COUNT_WIDTH, + C_DEFAULT_VALUE, + C_DIN_WIDTH, + C_DOUT_RST_VAL, + C_DOUT_WIDTH, + C_ENABLE_RLOCS, + C_FAMILY,//Not allowed in Verilog model + C_HAS_ALMOST_EMPTY, + C_HAS_ALMOST_FULL, + C_HAS_BACKUP, + C_HAS_DATA_COUNT, + C_HAS_MEMINIT_FILE, + C_HAS_OVERFLOW, + C_HAS_RD_DATA_COUNT, + C_HAS_RD_RST, + C_HAS_RST, + C_HAS_UNDERFLOW, + C_HAS_VALID, + C_HAS_WR_ACK, + C_HAS_WR_DATA_COUNT, + C_HAS_WR_RST, + C_IMPLEMENTATION_TYPE, + C_INIT_WR_PNTR_VAL, + C_MEMORY_TYPE, + C_MIF_FILE_NAME, + C_OPTIMIZATION_MODE, + C_OVERFLOW_LOW, + C_PRELOAD_LATENCY, + C_PRELOAD_REGS, + C_PROG_EMPTY_THRESH_ASSERT_VAL, + C_PROG_EMPTY_THRESH_NEGATE_VAL, + C_PROG_EMPTY_TYPE, + C_PROG_FULL_THRESH_ASSERT_VAL, + C_PROG_FULL_THRESH_NEGATE_VAL, + C_PROG_FULL_TYPE, + C_RD_DATA_COUNT_WIDTH, + C_RD_DEPTH, + C_RD_PNTR_WIDTH, + C_UNDERFLOW_LOW, + C_VALID_LOW, + C_WR_ACK_LOW, + C_WR_DATA_COUNT_WIDTH, + C_WR_DEPTH, + C_WR_PNTR_WIDTH, + C_WR_RESPONSE_LATENCY, + C_FULL_FLAGS_RST_VAL, + C_USE_FWFT_DATA_COUNT, + C_USE_EMBEDDED_REG + ) + gen_as + ( + .WR_CLK (WR_CLK), + .RD_CLK (RD_CLK), + .RST (RST), + .DIN (DIN), + .WR_EN (WR_EN), + .RD_EN (RD_EN_FIFO_IN), + .PROG_EMPTY_THRESH (PROG_EMPTY_THRESH), + .PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT), + .PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE), + .PROG_FULL_THRESH (PROG_FULL_THRESH), + .PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT), + .PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE), + .DOUT (DOUT_FIFO_OUT), + .FULL (FULL_FIFO_OUT), + .ALMOST_FULL (ALMOST_FULL_FIFO_OUT), + .WR_ACK (WR_ACK_FIFO_OUT), + .OVERFLOW (OVERFLOW_FIFO_OUT), + .EMPTY (EMPTY_FIFO_OUT), + .ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT), + .VALID (VALID_FIFO_OUT), + .UNDERFLOW (UNDERFLOW_FIFO_OUT), + .RD_DATA_COUNT (RD_DATA_COUNT_FIFO_OUT), + .WR_DATA_COUNT (WR_DATA_COUNT_FIFO_OUT), + .PROG_FULL (PROG_FULL_FIFO_OUT), + .PROG_EMPTY (PROG_EMPTY_FIFO_OUT) + ); +end + +default : begin : block1 + fifo_generator_v4_3_bhv_ver_as + #( + C_COMMON_CLOCK, + C_COUNT_TYPE, + C_DATA_COUNT_WIDTH, + C_DEFAULT_VALUE, + C_DIN_WIDTH, + C_DOUT_RST_VAL, + C_DOUT_WIDTH, + C_ENABLE_RLOCS, + C_FAMILY,//Not allowed in Verilog model + C_HAS_ALMOST_EMPTY, + C_HAS_ALMOST_FULL, + C_HAS_BACKUP, + C_HAS_DATA_COUNT, + C_HAS_MEMINIT_FILE, + C_HAS_OVERFLOW, + C_HAS_RD_DATA_COUNT, + C_HAS_RD_RST, + C_HAS_RST, + C_HAS_UNDERFLOW, + C_HAS_VALID, + C_HAS_WR_ACK, + C_HAS_WR_DATA_COUNT, + C_HAS_WR_RST, + C_IMPLEMENTATION_TYPE, + C_INIT_WR_PNTR_VAL, + C_MEMORY_TYPE, + C_MIF_FILE_NAME, + C_OPTIMIZATION_MODE, + C_OVERFLOW_LOW, + C_PRELOAD_LATENCY, + C_PRELOAD_REGS, + C_PROG_EMPTY_THRESH_ASSERT_VAL, + C_PROG_EMPTY_THRESH_NEGATE_VAL, + C_PROG_EMPTY_TYPE, + C_PROG_FULL_THRESH_ASSERT_VAL, + C_PROG_FULL_THRESH_NEGATE_VAL, + C_PROG_FULL_TYPE, + C_RD_DATA_COUNT_WIDTH, + C_RD_DEPTH, + C_RD_PNTR_WIDTH, + C_UNDERFLOW_LOW, + C_VALID_LOW, + C_WR_ACK_LOW, + C_WR_DATA_COUNT_WIDTH, + C_WR_DEPTH, + C_WR_PNTR_WIDTH, + C_WR_RESPONSE_LATENCY, + C_FULL_FLAGS_RST_VAL, + C_USE_FWFT_DATA_COUNT, + C_USE_EMBEDDED_REG + ) + gen_as + ( + .WR_CLK (WR_CLK), + .RD_CLK (RD_CLK), + .RST (RST), + .DIN (DIN), + .WR_EN (WR_EN), + .RD_EN (RD_EN_FIFO_IN), + .PROG_EMPTY_THRESH (PROG_EMPTY_THRESH), + .PROG_EMPTY_THRESH_ASSERT (PROG_EMPTY_THRESH_ASSERT), + .PROG_EMPTY_THRESH_NEGATE (PROG_EMPTY_THRESH_NEGATE), + .PROG_FULL_THRESH (PROG_FULL_THRESH), + .PROG_FULL_THRESH_ASSERT (PROG_FULL_THRESH_ASSERT), + .PROG_FULL_THRESH_NEGATE (PROG_FULL_THRESH_NEGATE), + .DOUT (DOUT_FIFO_OUT), + .FULL (FULL_FIFO_OUT), + .ALMOST_FULL (ALMOST_FULL_FIFO_OUT), + .WR_ACK (WR_ACK_FIFO_OUT), + .OVERFLOW (OVERFLOW_FIFO_OUT), + .EMPTY (EMPTY_FIFO_OUT), + .ALMOST_EMPTY (ALMOST_EMPTY_FIFO_OUT), + .VALID (VALID_FIFO_OUT), + .UNDERFLOW (UNDERFLOW_FIFO_OUT), + .RD_DATA_COUNT (RD_DATA_COUNT_FIFO_OUT), + .WR_DATA_COUNT (WR_DATA_COUNT_FIFO_OUT), + .PROG_FULL (PROG_FULL_FIFO_OUT), + .PROG_EMPTY (PROG_EMPTY_FIFO_OUT) + ); +end + +endcase +endgenerate + + +//************************************************************************** +// Connect Internal Signals +// (Signals labeled internal_*) +// In the normal case, these signals tie directly to the FIFO's inputs and +// outputs. +// In the case of Preload Latency 0 or 1, there are intermediate +// signals between the internal FIFO and the preload logic. +//************************************************************************** + +generate +if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) + begin : block2 + +fifo_generator_v4_3_bhv_ver_preload0 + #( + C_DOUT_RST_VAL, + C_DOUT_WIDTH, + C_HAS_RST, + C_VALID_LOW, + C_UNDERFLOW_LOW + ) + fgpl0 +( + .RD_CLK (RD_CLK_P0_IN), + .RD_RST (RST_P0_IN), + .RD_EN (RD_EN_P0_IN), + .FIFOEMPTY (EMPTY_P0_IN), + .FIFODATA (DATA_P0_IN), + .USERDATA (DATA_P0_OUT), + .USERVALID (VALID_P0_OUT), + .USEREMPTY (EMPTY_P0_OUT), + .USERALMOSTEMPTY (ALMOSTEMPTY_P0_OUT), + .USERUNDERFLOW (UNDERFLOW_P0_OUT), + .RAMVALID (RAMVALID_P0_OUT), + .FIFORDEN (RDEN_P0_OUT) + ); + + assign RD_CLK_P0_IN = ((C_VERILOG_IMPL == 0) ? CLK : RD_CLK); + assign RST_P0_IN = RST; + assign RD_EN_P0_IN = RD_EN; + + assign RD_EN_FIFO_IN = RDEN_P0_OUT; + + assign DOUT = DATA_P0_OUT; + assign DATA_P0_IN = DOUT_FIFO_OUT; + assign VALID = VALID_P0_OUT ; + assign EMPTY = EMPTY_P0_OUT; + assign ALMOST_EMPTY = ALMOSTEMPTY_P0_OUT; + assign EMPTY_P0_IN = EMPTY_FIFO_OUT; + assign UNDERFLOW = UNDERFLOW_P0_OUT ; + + always @ (posedge RD_CLK or posedge RST) + begin + if (RST) + begin + EMPTY_P0_OUT_Q <= 1; + ALMOSTEMPTY_P0_OUT_Q <= 1; + end + else + begin + EMPTY_P0_OUT_Q <= EMPTY_P0_OUT; + ALMOSTEMPTY_P0_OUT_Q <= ALMOSTEMPTY_P0_OUT; + end + end + + end +else + begin : block2 + + assign RD_CLK_P0_IN = 0; + assign RST_P0_IN = 0; + assign RD_EN_P0_IN = 0; + + assign RD_EN_FIFO_IN = RD_EN; + + assign DOUT = DOUT_FIFO_OUT; + assign DATA_P0_IN = 0; + assign VALID = VALID_FIFO_OUT; + assign EMPTY = EMPTY_FIFO_OUT; + assign ALMOST_EMPTY = ALMOST_EMPTY_FIFO_OUT; + assign EMPTY_P0_IN = 0; + assign UNDERFLOW = UNDERFLOW_FIFO_OUT; + + end +endgenerate + + +//Connect Data Count Signals +generate +if (C_USE_FWFT_DATA_COUNT==1) begin : block3 + assign RD_DATA_COUNT = (EMPTY_P0_OUT_Q | RST) ? 0 : (ALMOSTEMPTY_P0_OUT_Q ? 1 : RD_DATA_COUNT_FIFO_OUT); +end +else begin : block3 + assign RD_DATA_COUNT = RD_DATA_COUNT_FIFO_OUT; +end +endgenerate + +generate +if (C_USE_FWFT_DATA_COUNT==1) begin : block4 + assign WR_DATA_COUNT = WR_DATA_COUNT_FIFO_OUT; +end +else begin : block4 + assign WR_DATA_COUNT = WR_DATA_COUNT_FIFO_OUT; +end +endgenerate + + + assign FULL = FULL_FIFO_OUT; + assign ALMOST_FULL = ALMOST_FULL_FIFO_OUT; + assign WR_ACK = WR_ACK_FIFO_OUT; + assign OVERFLOW = OVERFLOW_FIFO_OUT; + assign PROG_FULL = PROG_FULL_FIFO_OUT; + assign PROG_EMPTY = PROG_EMPTY_FIFO_OUT; + assign DATA_COUNT = DATA_COUNT_FIFO_OUT; + + + // if an asynchronous FIFO has been selected, display a message that the FIFO + // will not be cycle-accurate in simulation + initial begin + //if (C_IMPLEMENTATION_TYPE == 1) begin //bug in v3.1 + if (C_IMPLEMENTATION_TYPE == 2) begin //fixed in v3.2 (IP2_Im) + $display("Warning in %m at time %t: When using an asynchronous configuration for the FIFO Generator, the behavioral model is not cycle-accurate. You may wish to choose the structural simulation model instead of the behavioral model. This will ensure accurate behavior and latencies during simulation. You can enable this from CORE Generator by selecting Project -> Project Options -> Generation tab -> Structural Simulation. See the FIFO Generator User Guide for more information.", $time); + end else if (C_IMPLEMENTATION_TYPE == 3 || C_IMPLEMENTATION_TYPE == 4) begin + $display("Failure in %m at time %t: Use of Virtex-4 and Virtex-5 built-in FIFO configurations is currently not supported. Please use the structural simulation model. You can enable this from CORE Generator by selecting Project -> Project Options -> Generation tab -> Structural Simulation. See the FIFO Generator User Guide for more information.", $time); + $finish; + end + + end + +endmodule //fifo_generator_v4_3_bhv_ver + + + + + + +/******************************************************************************* + * Declaration of asynchronous FIFO Module + ******************************************************************************/ +module fifo_generator_v4_3_bhv_ver_as + ( + WR_CLK, RD_CLK, RST, DIN, WR_EN, RD_EN, + PROG_EMPTY_THRESH, PROG_EMPTY_THRESH_ASSERT, PROG_EMPTY_THRESH_NEGATE, + PROG_FULL_THRESH, PROG_FULL_THRESH_ASSERT, PROG_FULL_THRESH_NEGATE, + DOUT, FULL, ALMOST_FULL, WR_ACK, OVERFLOW, EMPTY, ALMOST_EMPTY, VALID, + UNDERFLOW, RD_DATA_COUNT, WR_DATA_COUNT, PROG_FULL, PROG_EMPTY + ); + + /***************************************************************************** + * Declare user parameters and their defaults + *****************************************************************************/ + parameter C_COMMON_CLOCK = 0; + parameter C_COUNT_TYPE = 0; + parameter C_DATA_COUNT_WIDTH = 2; + parameter C_DEFAULT_VALUE = ""; + parameter C_DIN_WIDTH = 8; + parameter C_DOUT_RST_VAL = ""; + parameter C_DOUT_WIDTH = 8; + parameter C_ENABLE_RLOCS = 0; + parameter C_FAMILY = "virtex2"; //Not allowed in Verilog model + parameter C_HAS_ALMOST_EMPTY = 0; + parameter C_HAS_ALMOST_FULL = 0; + parameter C_HAS_BACKUP = 0; + parameter C_HAS_DATA_COUNT = 0; + parameter C_HAS_MEMINIT_FILE = 0; + parameter C_HAS_OVERFLOW = 0; + parameter C_HAS_RD_DATA_COUNT = 0; + parameter C_HAS_RD_RST = 0; + parameter C_HAS_RST = 0; + parameter C_HAS_UNDERFLOW = 0; + parameter C_HAS_VALID = 0; + parameter C_HAS_WR_ACK = 0; + parameter C_HAS_WR_DATA_COUNT = 0; + parameter C_HAS_WR_RST = 0; + parameter C_IMPLEMENTATION_TYPE = 0; + parameter C_INIT_WR_PNTR_VAL = 0; + parameter C_MEMORY_TYPE = 1; + parameter C_MIF_FILE_NAME = ""; + parameter C_OPTIMIZATION_MODE = 0; + parameter C_OVERFLOW_LOW = 0; + parameter C_PRELOAD_LATENCY = 1; + parameter C_PRELOAD_REGS = 0; + parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0; + parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0; + parameter C_PROG_EMPTY_TYPE = 0; + parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0; + parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0; + parameter C_PROG_FULL_TYPE = 0; + parameter C_RD_DATA_COUNT_WIDTH = 2; + parameter C_RD_DEPTH = 256; + parameter C_RD_PNTR_WIDTH = 8; + parameter C_UNDERFLOW_LOW = 0; + parameter C_VALID_LOW = 0; + parameter C_WR_ACK_LOW = 0; + parameter C_WR_DATA_COUNT_WIDTH = 2; + parameter C_WR_DEPTH = 256; + parameter C_WR_PNTR_WIDTH = 8; + parameter C_WR_RESPONSE_LATENCY = 1; + parameter C_FULL_FLAGS_RST_VAL = 1; + parameter C_USE_FWFT_DATA_COUNT = 0; + parameter C_USE_EMBEDDED_REG = 0; + + /***************************************************************************** + * Declare Input and Output Ports + *****************************************************************************/ + input [C_DIN_WIDTH-1:0] DIN; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE; + input RD_CLK; + input RD_EN; + input RST; + input WR_CLK; + input WR_EN; + output ALMOST_EMPTY; + output ALMOST_FULL; + output [C_DOUT_WIDTH-1:0] DOUT; + output EMPTY; + output FULL; + output OVERFLOW; + output PROG_EMPTY; + output PROG_FULL; + output VALID; + output [C_RD_DATA_COUNT_WIDTH-1:0] RD_DATA_COUNT; + output UNDERFLOW; + output WR_ACK; + output [C_WR_DATA_COUNT_WIDTH-1:0] WR_DATA_COUNT; + + /******************************************************************************* + * Input and output register declarations + ******************************************************************************/ + /******************************************************************************* + * Parameters used as constants + ******************************************************************************/ + //When RST is present, set FULL reset value to '1'. + //If core has no RST, make sure FULL powers-on as '0'. + parameter C_DEPTH_RATIO_WR = + (C_WR_DEPTH>C_RD_DEPTH) ? (C_WR_DEPTH/C_RD_DEPTH) : 1; + parameter C_DEPTH_RATIO_RD = + (C_RD_DEPTH>C_WR_DEPTH) ? (C_RD_DEPTH/C_WR_DEPTH) : 1; + parameter C_FIFO_WR_DEPTH = + (C_COMMON_CLOCK) ? + C_WR_DEPTH : C_WR_DEPTH - 1; + parameter C_FIFO_RD_DEPTH = + (C_COMMON_CLOCK) ? + C_RD_DEPTH : C_RD_DEPTH - 1; + + + // EXTRA_WORDS = 2 * C_DEPTH_RATIO_WR / C_DEPTH_RATIO_RD + // WR_DEPTH : RD_DEPTH = 1:2 => EXTRA_WORDS = 1 + // WR_DEPTH : RD_DEPTH = 1:4 => EXTRA_WORDS = 1 (rounded to ceiling) + // WR_DEPTH : RD_DEPTH = 2:1 => EXTRA_WORDS = 4 + // WR_DEPTH : RD_DEPTH = 4:1 => EXTRA_WORDS = 8 + parameter EXTRA_WORDS = (C_DEPTH_RATIO_RD > 1)? 1:(2 * C_DEPTH_RATIO_WR); + // extra_words_dc = 2 * C_DEPTH_RATIO_WR / C_DEPTH_RATIO_RD + // C_DEPTH_RATIO_WR | C_DEPTH_RATIO_RD | C_PNTR_WIDTH | EXTRA_WORDS_DC + // -----------------|------------------|-----------------|--------------- + // 1 | 8 | C_RD_PNTR_WIDTH | 2 + // 1 | 4 | C_RD_PNTR_WIDTH | 2 + // 1 | 2 | C_RD_PNTR_WIDTH | 2 + // 1 | 1 | C_WR_PNTR_WIDTH | 2 + // 2 | 1 | C_WR_PNTR_WIDTH | 4 + // 4 | 1 | C_WR_PNTR_WIDTH | 8 + // 8 | 1 | C_WR_PNTR_WIDTH | 16 + parameter EXTRA_WORDS_DC = (C_DEPTH_RATIO_WR)? + 2:(2 * C_DEPTH_RATIO_WR/C_DEPTH_RATIO_RD); + + + //Memory which will be used to simulate a FIFO + reg [C_DIN_WIDTH-1:0] memory[C_WR_DEPTH-1:0]; + reg [31:0] num_wr_bits; + reg [31:0] num_rd_bits; + reg [31:0] next_num_wr_bits; + reg [31:0] next_num_rd_bits; + reg [31:0] wr_ptr; + reg [31:0] rd_ptr; + reg [31:0] wr_ptr_rdclk; + reg [31:0] wr_ptr_rdclk_next; + reg [31:0] rd_ptr_wrclk; + reg [31:0] rd_ptr_wrclk_next; + wire [31:0] num_read_words = num_rd_bits/C_DOUT_WIDTH; + wire [31:0] num_read_words_dc_i; + wire [31:0] num_read_words_dc = num_rd_bits/C_DOUT_WIDTH; + wire [31:0] num_read_words_fwft_dc = (num_rd_bits/C_DOUT_WIDTH+2); + wire [31:0] num_read_words_pe = + num_rd_bits/(C_DOUT_WIDTH/C_DEPTH_RATIO_WR); + wire [C_RD_DATA_COUNT_WIDTH-1:0] num_read_words_sized_i; + wire [C_RD_DATA_COUNT_WIDTH-1:0] num_read_words_sized + = num_read_words_dc_i[C_RD_PNTR_WIDTH-1 : C_RD_PNTR_WIDTH-C_RD_DATA_COUNT_WIDTH]; + wire [C_RD_DATA_COUNT_WIDTH-1:0] num_read_words_sized_fwft + = num_read_words_dc_i[C_RD_PNTR_WIDTH : C_RD_PNTR_WIDTH-C_RD_DATA_COUNT_WIDTH+1]; + wire [31:0] num_write_words = num_wr_bits/C_DIN_WIDTH; + wire [31:0] num_write_words_dc_i; + wire [31:0] num_write_words_dc = 1+(num_wr_bits-1)/C_DIN_WIDTH;//roof of num_wr_bits/C_DIN_WIDTH + wire [31:0] num_write_words_fwft_dc = + (num_wr_bits/C_DIN_WIDTH*C_DEPTH_RATIO_RD+2*C_DEPTH_RATIO_WR)/C_DEPTH_RATIO_RD; + wire [31:0] num_write_words_pf = + num_wr_bits/(C_DIN_WIDTH/C_DEPTH_RATIO_RD); + wire [C_WR_DATA_COUNT_WIDTH-1:0] num_write_words_sized_i; + wire [C_WR_DATA_COUNT_WIDTH-1:0] num_write_words_sized + = num_write_words_dc_i[C_WR_PNTR_WIDTH-1 : C_WR_PNTR_WIDTH-C_WR_DATA_COUNT_WIDTH]; + wire [C_WR_DATA_COUNT_WIDTH-1:0] num_write_words_sized_fwft + = num_write_words_dc_i[C_WR_PNTR_WIDTH : C_WR_PNTR_WIDTH-C_WR_DATA_COUNT_WIDTH+1]; + wire [31:0] reads_per_write = C_DIN_WIDTH/C_DOUT_WIDTH; + wire [31:0] log2_reads_per_write = log2_val(reads_per_write); + wire [31:0] writes_per_read = C_DOUT_WIDTH/C_DIN_WIDTH; + wire [31:0] log2_writes_per_read = log2_val(writes_per_read); + + /******************************************************************************* + * Internal Registers and wires + ******************************************************************************/ + wire wr_ack_i; + wire overflow_i; + wire underflow_i; + wire valid_i; + wire valid_out; + reg valid_d1; + /******************************************************************************* + * Internal registers and wires for internal reset logics + ******************************************************************************/ + reg rd_rst_asreg =0; + reg rd_rst_asreg_d1 =0; + reg rd_rst_asreg_d2 =0; + reg rd_rst_reg =0; + reg rd_rst_d1 =0; + reg wr_rst_asreg =0; + reg wr_rst_asreg_d1 =0; + reg wr_rst_asreg_d2 =0; + reg wr_rst_reg =0; + reg wr_rst_d1 =0; + wire rd_rst_comb; + wire rd_rst_i; + wire wr_rst_comb; + wire wr_rst_i; + + + + //Special ideal FIFO signals + reg [C_DOUT_WIDTH-1:0] ideal_dout; + wire [C_DOUT_WIDTH-1:0] ideal_dout_out; + reg [C_DOUT_WIDTH-1:0] ideal_dout_d1; + reg ideal_wr_ack; + reg ideal_valid; + reg ideal_overflow; + reg ideal_underflow; + reg ideal_full; + reg ideal_empty; + reg ideal_almost_full; + reg ideal_almost_empty; + reg ideal_prog_full; + reg ideal_prog_empty; + + //MSBs of the counts + reg [C_WR_DATA_COUNT_WIDTH-1 : 0] ideal_wr_count; + reg [C_RD_DATA_COUNT_WIDTH-1 : 0] ideal_rd_count; + + //user specified value for reseting the size of the fifo + reg [C_DOUT_WIDTH-1:0] dout_reset_val; + + //temporary registers for WR_RESPONSE_LATENCY feature + + integer tmp_wr_listsize; + integer tmp_rd_listsize; + + //Signal for registered version of prog full and empty + reg prog_full_d; + reg prog_empty_d; + + //Threshold values for Programmable Flags + integer prog_empty_actual_thresh_assert; + integer prog_empty_actual_thresh_negate; + integer prog_full_actual_thresh_assert; + integer prog_full_actual_thresh_negate; + + + /**************************************************************************** + * Function Declarations + ***************************************************************************/ + + task write_fifo; + begin + memory[wr_ptr] <= DIN; + if (wr_ptr == 0) begin + wr_ptr <= C_WR_DEPTH - 1; + end else begin + wr_ptr <= wr_ptr - 1; + end + end + endtask // write_fifo + + task read_fifo; + integer i; + reg [C_DOUT_WIDTH-1:0] tmp_dout; + reg [C_DIN_WIDTH-1:0] memory_read; + reg [31:0] tmp_rd_ptr; + reg [31:0] rd_ptr_high; + reg [31:0] rd_ptr_low; + begin + // output is wider than input + if (reads_per_write == 0) begin + tmp_dout = 0; + tmp_rd_ptr = (rd_ptr << log2_writes_per_read)+(writes_per_read-1); + for (i = writes_per_read - 1; i >= 0; i = i - 1) begin + tmp_dout = tmp_dout << C_DIN_WIDTH; + tmp_dout = tmp_dout | memory[tmp_rd_ptr]; + if (tmp_rd_ptr == 0) begin + tmp_rd_ptr = C_WR_DEPTH - 1; + end else begin + tmp_rd_ptr = tmp_rd_ptr - 1; + end + end + + // output is symmetric + end else if (reads_per_write == 1) begin + tmp_dout = memory[rd_ptr]; + + // input is wider than output + end else begin + rd_ptr_high = rd_ptr >> log2_reads_per_write; + rd_ptr_low = rd_ptr & (reads_per_write - 1); + memory_read = memory[rd_ptr_high]; + tmp_dout = memory_read >> (rd_ptr_low*C_DOUT_WIDTH); + end + ideal_dout <= tmp_dout; + if (rd_ptr == 0) begin + rd_ptr <= C_RD_DEPTH - 1; + end else begin + rd_ptr <= rd_ptr - 1; + end + end + endtask + + /**************************************************************************** + * log2_val + * Returns the 'log2' value for the input value for the supported ratios + ***************************************************************************/ + function [31:0] log2_val; + input [31:0] binary_val; + + begin + if (binary_val == 8) begin + log2_val = 3; + end else if (binary_val == 4) begin + log2_val = 2; + end else begin + log2_val = 1; + end + end + endfunction + + /************************************************************************* + * hexstr_conv + * Converts a string of type hex to a binary value (for C_DOUT_RST_VAL) + ***********************************************************************/ + function [C_DOUT_WIDTH-1:0] hexstr_conv; + input [(C_DOUT_WIDTH*8)-1:0] def_data; + + integer index,i,j; + reg [3:0] bin; + + begin + index = 0; + hexstr_conv = 'b0; + for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 ) + begin + case (def_data[7:0]) + 8'b00000000 : + begin + bin = 4'b0000; + i = -1; + end + 8'b00110000 : bin = 4'b0000; + 8'b00110001 : bin = 4'b0001; + 8'b00110010 : bin = 4'b0010; + 8'b00110011 : bin = 4'b0011; + 8'b00110100 : bin = 4'b0100; + 8'b00110101 : bin = 4'b0101; + 8'b00110110 : bin = 4'b0110; + 8'b00110111 : bin = 4'b0111; + 8'b00111000 : bin = 4'b1000; + 8'b00111001 : bin = 4'b1001; + 8'b01000001 : bin = 4'b1010; + 8'b01000010 : bin = 4'b1011; + 8'b01000011 : bin = 4'b1100; + 8'b01000100 : bin = 4'b1101; + 8'b01000101 : bin = 4'b1110; + 8'b01000110 : bin = 4'b1111; + 8'b01100001 : bin = 4'b1010; + 8'b01100010 : bin = 4'b1011; + 8'b01100011 : bin = 4'b1100; + 8'b01100100 : bin = 4'b1101; + 8'b01100101 : bin = 4'b1110; + 8'b01100110 : bin = 4'b1111; + default : + begin + bin = 4'bx; + end + endcase + for( j=0; j<4; j=j+1) + begin + if ((index*4)+j < C_DOUT_WIDTH) + begin + hexstr_conv[(index*4)+j] = bin[j]; + end + end + index = index + 1; + def_data = def_data >> 8; + end + end + endfunction + + /************************************************************************* + * Initialize Signals for clean power-on simulation + *************************************************************************/ + initial + begin + num_wr_bits = 0; + num_rd_bits = 0; + next_num_wr_bits = 0; + next_num_rd_bits = 0; + rd_ptr = C_RD_DEPTH - 1; + wr_ptr = C_WR_DEPTH - 1; + rd_ptr_wrclk = rd_ptr; + wr_ptr_rdclk = wr_ptr; + dout_reset_val = hexstr_conv(C_DOUT_RST_VAL); + ideal_dout = dout_reset_val; + ideal_wr_ack = 1'b0; + ideal_valid = 1'b0; + ideal_overflow = 1'b0; + ideal_underflow = 1'b0; + //Modified the start-up value of FULL to '0' in v3.2 (IP2_Im) + //ideal_full = C_FULL_RESET_VAL; //was in v3.1 + ideal_full = 1'b0; //v3.2 + ideal_empty = 1'b1; + //Modified the start-up value of ALMOST_FULL to '0' in v3.2 (IP2_Im) + //ideal_almost_full = C_ALMOST_FULL_RESET_VAL; //was in v3.1 + ideal_almost_full = 1'b0; //v3.2 + ideal_almost_empty = 1'b1; + ideal_wr_count = 0; + ideal_rd_count = 0; + //Modified the start-up value of PROG_FULL to '0' in v3.2 (IP2_Im) + //ideal_prog_full = C_PROG_FULL_RESET_VAL; //was in v3.1 + ideal_prog_full = 1'b0; //v3.2 + ideal_prog_empty = 1'b1; + //Modified the start-up value of PROG_FULL to '0' in v3.2 (IP2_Im) + //Therefore, prog_full_d has to start-up at '0' too + //prog_full_d = C_PROG_FULL_RESET_VAL; //was in v3.1 + prog_full_d = 1'b0; //v3.2 + prog_empty_d = 1'b1; + end + + + + /************************************************************************* + * Assign Internal ideal signals to output ports + *************************************************************************/ + assign ideal_dout_out= (C_PRELOAD_LATENCY==2 && + (C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))? + ideal_dout_d1: ideal_dout; + assign DOUT = ideal_dout_out; + assign FULL = ideal_full; + assign EMPTY = ideal_empty; + assign ALMOST_FULL = ideal_almost_full; + assign ALMOST_EMPTY = ideal_almost_empty; + assign num_write_words_sized_i=C_USE_FWFT_DATA_COUNT? + num_write_words_sized_fwft:num_write_words_sized; + assign num_read_words_sized_i=C_USE_FWFT_DATA_COUNT? + num_read_words_sized_fwft:num_read_words_sized; + assign num_write_words_dc_i = C_USE_FWFT_DATA_COUNT? + num_write_words_fwft_dc: num_write_words_dc; + assign num_read_words_dc_i = C_USE_FWFT_DATA_COUNT? + num_read_words_fwft_dc: num_read_words_dc; + assign WR_DATA_COUNT = ideal_wr_count; + assign RD_DATA_COUNT = ideal_rd_count; + assign PROG_FULL = ideal_prog_full; + assign PROG_EMPTY = ideal_prog_empty; + + //Handshaking signals can be active low, depending on _LOW parameters + assign valid_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & ~EMPTY) : ideal_valid; + assign VALID = valid_out ? !C_VALID_LOW : C_VALID_LOW; + assign valid_out = (C_PRELOAD_LATENCY==2 && + (C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))? + valid_d1: valid_i; + assign underflow_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & EMPTY) : ideal_underflow; + assign UNDERFLOW = underflow_i ? !C_UNDERFLOW_LOW : C_UNDERFLOW_LOW; + + assign WR_ACK = wr_ack_i ? !C_WR_ACK_LOW : C_WR_ACK_LOW; + assign wr_ack_i = (C_WR_RESPONSE_LATENCY==1) ? ideal_wr_ack : + (WR_EN & !FULL); + assign OVERFLOW = overflow_i ? !C_OVERFLOW_LOW : C_OVERFLOW_LOW; + assign overflow_i = (C_WR_RESPONSE_LATENCY==1) ? ideal_overflow : + (WR_EN & FULL); + + /******************************************************************************* + * Internal reset logics + ******************************************************************************/ + assign wr_rst_comb = !wr_rst_asreg_d2 && wr_rst_asreg; + assign rd_rst_comb = !rd_rst_asreg_d2 && rd_rst_asreg; + assign wr_rst_i = C_HAS_RST ? wr_rst_reg : 0; + assign rd_rst_i = C_HAS_RST ? rd_rst_reg : 0; + + + always @(posedge RD_CLK or posedge rd_rst_i) begin + if (rd_rst_i == 1'b1) begin + valid_d1 <= 1'b0; + end else begin + valid_d1 <= valid_i; + end + end + always @(posedge RD_CLK or posedge rd_rst_i) begin + if (rd_rst_i == 1'b1) begin + ideal_dout_d1 <= dout_reset_val; + end else begin + ideal_dout_d1 <= ideal_dout; + end + end + + always @(posedge WR_CLK or posedge RST) begin + if (RST == 1'b1) begin + wr_rst_asreg <= 1'b1; + end else begin + if (wr_rst_asreg_d1 == 1'b1) begin + wr_rst_asreg <= 1'b0; + end else begin + wr_rst_asreg <= wr_rst_asreg; + end + end + end + + always @(posedge WR_CLK) begin + wr_rst_asreg_d1 <= wr_rst_asreg; + wr_rst_asreg_d2 <= wr_rst_asreg_d1; + end + + always @(posedge WR_CLK or posedge wr_rst_comb) begin + if (wr_rst_comb == 1'b1) begin + wr_rst_reg <= 1'b1; + end else begin + wr_rst_reg <= 1'b0; + end + end + + always @(posedge WR_CLK or posedge wr_rst_i) begin + if (wr_rst_i == 1'b1) begin + wr_rst_d1 <= 1'b1; + end else begin + wr_rst_d1 <= wr_rst_i; + end + end + always @(posedge RD_CLK or posedge RST) begin + if (RST == 1'b1) begin + rd_rst_asreg <= 1'b1; + end else begin + if (rd_rst_asreg_d1 == 1'b1) begin + rd_rst_asreg <= 1'b0; + end else begin + rd_rst_asreg <= rd_rst_asreg; + end + end + end + + always @(posedge RD_CLK) begin + rd_rst_asreg_d1 <= rd_rst_asreg; + rd_rst_asreg_d2 <= rd_rst_asreg_d1; + end + + always @(posedge RD_CLK or posedge rd_rst_comb) begin + if (rd_rst_comb == 1'b1) begin + rd_rst_reg <= 1'b1; + end else begin + rd_rst_reg <= 1'b0; + end + end + + //Generate overflow and underflow flags seperately + //because they don't support async rst + always @(posedge WR_CLK) begin + ideal_overflow <= WR_EN & ideal_full; + end + always @(posedge RD_CLK) begin + ideal_underflow <= ideal_empty & RD_EN; + end + + /******************************************************************************* + * Write and Read Logics + ******************************************************************************/ + always @(posedge WR_CLK or posedge wr_rst_i) begin : gen_fifo_w + + /****** Reset fifo (case 1)***************************************/ + if (wr_rst_i == 1'b1) begin + num_wr_bits <= 0; + next_num_wr_bits <= 0; + wr_ptr <= C_WR_DEPTH - 1; + rd_ptr_wrclk <= C_RD_DEPTH - 1; + ideal_wr_ack <= 0; + ideal_full <= C_FULL_FLAGS_RST_VAL; + ideal_almost_full <= C_FULL_FLAGS_RST_VAL; + ideal_wr_count <= 0; + + ideal_prog_full <= C_FULL_FLAGS_RST_VAL; + prog_full_d <= C_FULL_FLAGS_RST_VAL; + + end else begin //wr_rst_i==0 + + //Determine the current number of words in the FIFO + tmp_wr_listsize = (C_DEPTH_RATIO_RD > 1) ? num_wr_bits/C_DOUT_WIDTH : + num_wr_bits/C_DIN_WIDTH; + rd_ptr_wrclk_next = rd_ptr; + if (rd_ptr_wrclk < rd_ptr_wrclk_next) begin + next_num_wr_bits = num_wr_bits - + C_DOUT_WIDTH*(rd_ptr_wrclk + C_RD_DEPTH + - rd_ptr_wrclk_next); + end else begin + next_num_wr_bits = num_wr_bits - + C_DOUT_WIDTH*(rd_ptr_wrclk - rd_ptr_wrclk_next); + end + + //If this is a write, handle the write by adding the value + // to the linked list, and updating all outputs appropriately + if (WR_EN == 1'b1) begin + if (ideal_full == 1'b1) begin + + //If the FIFO is full, do NOT perform the write, + // update flags accordingly + if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD + >= C_FIFO_WR_DEPTH) begin + //write unsuccessful - do not change contents + + //Do not acknowledge the write + ideal_wr_ack <= 0; + //Reminder that FIFO is still full + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + ideal_wr_count <= num_write_words_sized_i; + + //If the FIFO is one from full, but reporting full + end else if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD == + C_FIFO_WR_DEPTH-1) begin + //No change to FIFO + + //Write not successful + ideal_wr_ack <= 0; + //With DEPTH-1 words in the FIFO, it is almost_full + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + ideal_wr_count <= num_write_words_sized_i; + + + //If the FIFO is completely empty, but it is + // reporting FULL for some reason (like reset) + end else if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD <= + C_FIFO_WR_DEPTH-2) begin + //No change to FIFO + + //Write not successful + ideal_wr_ack <= 0; + //FIFO is really not close to full, so change flag status. + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + ideal_wr_count <= num_write_words_sized_i; + end //(tmp_wr_listsize == 0) + + end else begin + + //If the FIFO is full, do NOT perform the write, + // update flags accordingly + if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD >= + C_FIFO_WR_DEPTH) begin + //write unsuccessful - do not change contents + + //Do not acknowledge the write + ideal_wr_ack <= 0; + //Reminder that FIFO is still full + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + ideal_wr_count <= num_write_words_sized_i; + + //If the FIFO is one from full + end else if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD == + C_FIFO_WR_DEPTH-1) begin + //Add value on DIN port to FIFO + write_fifo; + next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH; + + //Write successful, so issue acknowledge + // and no error + ideal_wr_ack <= 1; + //This write is CAUSING the FIFO to go full + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + ideal_wr_count <= num_write_words_sized_i; + + //If the FIFO is 2 from full + end else if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD == + C_FIFO_WR_DEPTH-2) begin + //Add value on DIN port to FIFO + write_fifo; + next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH; + //Write successful, so issue acknowledge + // and no error + ideal_wr_ack <= 1; + //Still 2 from full + ideal_full <= 1'b0; + //2 from full, and writing, so set almost_full + ideal_almost_full <= 1'b1; + + ideal_wr_count <= num_write_words_sized_i; + + //If the FIFO is not close to being full + end else if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD < + C_FIFO_WR_DEPTH-2) begin + //Add value on DIN port to FIFO + write_fifo; + next_num_wr_bits = next_num_wr_bits + C_DIN_WIDTH; + //Write successful, so issue acknowledge + // and no error + ideal_wr_ack <= 1; + //Not even close to full. + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + ideal_wr_count <= num_write_words_sized_i; + + end + + end + + end else begin //(WR_EN == 1'b1) + + //If user did not attempt a write, then do not + // give ack or err + ideal_wr_ack <= 0; + + //Implied statements: + //ideal_empty <= ideal_empty; + //ideal_almost_empty <= ideal_almost_empty; + + //Check for full + if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD >= C_FIFO_WR_DEPTH) + ideal_full <= 1'b1; + else + ideal_full <= 1'b0; + + //Check for almost_full + if ((tmp_wr_listsize + C_DEPTH_RATIO_RD - 1)/C_DEPTH_RATIO_RD >= C_FIFO_WR_DEPTH-1) + ideal_almost_full <= 1'b1; + else + ideal_almost_full <= 1'b0; + + ideal_wr_count <= num_write_words_sized_i; + end + + /********************************************************* + * Programmable FULL flags + *********************************************************/ + //Single Programmable Full Constant Threshold + if (C_PROG_FULL_TYPE==1) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_full_actual_thresh_assert = C_PROG_FULL_THRESH_ASSERT_VAL-EXTRA_WORDS; + prog_full_actual_thresh_negate = C_PROG_FULL_THRESH_ASSERT_VAL-EXTRA_WORDS; + end else begin + prog_full_actual_thresh_assert = C_PROG_FULL_THRESH_ASSERT_VAL; + prog_full_actual_thresh_negate = C_PROG_FULL_THRESH_ASSERT_VAL; + end + + //Two Programmable Full Constant Thresholds + end else if (C_PROG_FULL_TYPE==2) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_full_actual_thresh_assert = C_PROG_FULL_THRESH_ASSERT_VAL-EXTRA_WORDS; + prog_full_actual_thresh_negate = C_PROG_FULL_THRESH_NEGATE_VAL-EXTRA_WORDS; + end else begin + prog_full_actual_thresh_assert = C_PROG_FULL_THRESH_ASSERT_VAL; + prog_full_actual_thresh_negate = C_PROG_FULL_THRESH_NEGATE_VAL; + end + + //Single Programmable Full Threshold Input + end else if (C_PROG_FULL_TYPE==3) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_full_actual_thresh_assert = PROG_FULL_THRESH-EXTRA_WORDS; + prog_full_actual_thresh_negate = PROG_FULL_THRESH-EXTRA_WORDS; + end else begin + prog_full_actual_thresh_assert = PROG_FULL_THRESH; + prog_full_actual_thresh_negate = PROG_FULL_THRESH; + end + + //Two Programmable Full Threshold Inputs + end else if (C_PROG_FULL_TYPE==4) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_full_actual_thresh_assert = PROG_FULL_THRESH_ASSERT-EXTRA_WORDS; + prog_full_actual_thresh_negate = PROG_FULL_THRESH_NEGATE-EXTRA_WORDS; + end else begin + prog_full_actual_thresh_assert = PROG_FULL_THRESH_ASSERT; + prog_full_actual_thresh_negate = PROG_FULL_THRESH_NEGATE; + end + end //C_PROG_FULL_TYPE + + if (num_write_words_pf==0) begin + prog_full_d <= 1'b0; + end else begin + if (((1+(num_write_words_pf-1)/C_DEPTH_RATIO_RD) + == prog_full_actual_thresh_assert-1) && WR_EN) begin + prog_full_d <= 1'b1; + end else if ((1+(num_write_words_pf-1)/C_DEPTH_RATIO_RD) + >= prog_full_actual_thresh_assert) begin + prog_full_d <= 1'b1; + end else if ((1+(num_write_words_pf-1)/C_DEPTH_RATIO_RD) + < prog_full_actual_thresh_negate) begin + prog_full_d <= 1'b0; + end + end + + if (wr_rst_d1==1 && wr_rst_i==0) begin + ideal_prog_full <= 0; + end else begin + ideal_prog_full <= prog_full_d; + end + num_wr_bits <= next_num_wr_bits; + rd_ptr_wrclk <= rd_ptr; + + end //wr_rst_i==0 + end // write always + + always @(posedge RD_CLK or posedge rd_rst_i) begin : gen_fifo_r + + /****** Reset fifo (case 1)***************************************/ + if (rd_rst_i) begin + num_rd_bits <= 0; + next_num_rd_bits <= 0; + rd_ptr <= C_RD_DEPTH -1; + wr_ptr_rdclk <= C_WR_DEPTH -1; + ideal_dout <= dout_reset_val; + ideal_valid <= 1'b0; + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + ideal_rd_count <= 0; + + ideal_prog_empty <= 1'b1; + prog_empty_d <= 1; + + + end else begin //rd_rst_i==0 + + //Determine the current number of words in the FIFO + tmp_rd_listsize = (C_DEPTH_RATIO_WR > 1) ? num_rd_bits/C_DIN_WIDTH : + num_rd_bits/C_DOUT_WIDTH; + wr_ptr_rdclk_next = wr_ptr; + + if (wr_ptr_rdclk < wr_ptr_rdclk_next) begin + next_num_rd_bits = num_rd_bits + + C_DIN_WIDTH*(wr_ptr_rdclk +C_WR_DEPTH + - wr_ptr_rdclk_next); + end else begin + next_num_rd_bits = num_rd_bits + + C_DIN_WIDTH*(wr_ptr_rdclk - wr_ptr_rdclk_next); + end + + /*****************************************************************/ + // Read Operation - Read Latency 1 + /*****************************************************************/ + if (C_PRELOAD_LATENCY==1 || C_PRELOAD_LATENCY==2) begin + + if (RD_EN == 1'b1) begin + + if (ideal_empty == 1'b1) begin + + //If the FIFO is completely empty, and is reporting empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) + begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Reminder that FIFO is still empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + end // if (tmp_rd_listsize <= 0) + + //If the FIFO is one from empty, but it is reporting empty + else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1) + begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Note that FIFO is no longer empty, but is almost empty (has one word left) + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize == 1) + + //If the FIFO is two from empty, and is reporting empty + else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) + begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Fifo has two words, so is neither empty or almost empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize == 2) + + //If the FIFO is not close to empty, but is reporting that it is + // Treat the FIFO as empty this time, but unset EMPTY flags. + if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && (tmp_rd_listsize/C_DEPTH_RATIO_WR<C_FIFO_RD_DEPTH)) + begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Note that the FIFO is No Longer Empty or Almost Empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1)) + end // else: if(ideal_empty == 1'b1) + + else //if (ideal_empty == 1'b0) + begin + + //If the FIFO is completely full, and we are successfully reading from it + if (tmp_rd_listsize/C_DEPTH_RATIO_WR >= C_FIFO_RD_DEPTH) + begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Not close to empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize == C_FIFO_RD_DEPTH) + + //If the FIFO is not close to being empty + else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && (tmp_rd_listsize/C_DEPTH_RATIO_WR<=C_FIFO_RD_DEPTH)) + begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Not close to empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1)) + + //If the FIFO is two from empty + else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) + begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Fifo is not yet empty. It is going almost_empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize == 2) + + //If the FIFO is one from empty + else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR == 1)) + begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Note that FIFO is GOING empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize == 1) + + + //If the FIFO is completely empty + else if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) + begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Reminder that FIFO is still empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize <= 0) + + end // if (ideal_empty == 1'b0) + + end //(RD_EN == 1'b1) + + else //if (RD_EN == 1'b0) + begin + //If user did not attempt a read, do not give an ack or err + ideal_valid <= 1'b0; + + //Check for empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) + ideal_empty <= 1'b1; + else + ideal_empty <= 1'b0; + + //Check for almost_empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 1) + ideal_almost_empty <= 1'b1; + else + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // else: !if(RD_EN == 1'b1) + + /*****************************************************************/ + // Read Operation - Read Latency 0 + /*****************************************************************/ + end else if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + if (RD_EN == 1'b1) begin + + if (ideal_empty == 1'b1) begin + + //If the FIFO is completely empty, and is reporting empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Reminder that FIFO is still empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is one from empty, but it is reporting empty + end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1) begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Note that FIFO is no longer empty, but is almost empty (has one word left) + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is two from empty, and is reporting empty + end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Fifo has two words, so is neither empty or almost empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is not close to empty, but is reporting that it is + // Treat the FIFO as empty this time, but unset EMPTY flags. + end else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && + (tmp_rd_listsize/C_DEPTH_RATIO_WR<C_FIFO_RD_DEPTH)) begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Note that the FIFO is No Longer Empty or Almost Empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // if ((tmp_rd_listsize > 2) && (tmp_rd_listsize<=C_FIFO_RD_DEPTH-1)) + + end else begin + + //If the FIFO is completely full, and we are successfully reading from it + if (tmp_rd_listsize/C_DEPTH_RATIO_WR >= C_FIFO_RD_DEPTH) begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Not close to empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is not close to being empty + end else if ((tmp_rd_listsize/C_DEPTH_RATIO_WR > 2) && + (tmp_rd_listsize/C_DEPTH_RATIO_WR<=C_FIFO_RD_DEPTH)) begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Not close to empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is two from empty + end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 2) begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Fifo is not yet empty. It is going almost_empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is one from empty + end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR == 1) begin + //Read the value from the FIFO + read_fifo; + next_num_rd_bits = next_num_rd_bits - C_DOUT_WIDTH; + + //Acknowledge the read from the FIFO, no error + ideal_valid <= 1'b1; + //Note that FIFO is GOING empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + //If the FIFO is completely empty + end else if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) begin + //Do not change the contents of the FIFO + + //Do not acknowledge the read from empty FIFO + ideal_valid <= 1'b0; + //Reminder that FIFO is still empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + ideal_rd_count <= num_read_words_sized_i; + + end // if (tmp_rd_listsize <= 0) + + end // if (ideal_empty == 1'b0) + + end else begin//(RD_EN == 1'b0) + + + //If user did not attempt a read, do not give an ack or err + ideal_valid <= 1'b0; + + //Check for empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 0) + ideal_empty <= 1'b1; + else + ideal_empty <= 1'b0; + + //Check for almost_empty + if (tmp_rd_listsize/C_DEPTH_RATIO_WR <= 1) + ideal_almost_empty <= 1'b1; + else + ideal_almost_empty <= 1'b0; + + ideal_rd_count <= num_read_words_sized_i; + + end // else: !if(RD_EN == 1'b1) + end //if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) + + + /********************************************************* + * Programmable EMPTY flags + *********************************************************/ + //Determine the Assert and Negate thresholds for Programmable Empty + // (Subtract 2 read-sized words when using Preload 0) + + //Single Programmable Empty Constant Threshold + if (C_PROG_EMPTY_TYPE==1) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_empty_actual_thresh_assert = C_PROG_EMPTY_THRESH_ASSERT_VAL-2; + prog_empty_actual_thresh_negate = C_PROG_EMPTY_THRESH_ASSERT_VAL-2; + end + else begin + prog_empty_actual_thresh_assert = C_PROG_EMPTY_THRESH_ASSERT_VAL; + prog_empty_actual_thresh_negate = C_PROG_EMPTY_THRESH_ASSERT_VAL; + end + + //Two Programmable Empty Constant Thresholds + end else if (C_PROG_EMPTY_TYPE==2) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_empty_actual_thresh_assert = C_PROG_EMPTY_THRESH_ASSERT_VAL-2; + prog_empty_actual_thresh_negate = C_PROG_EMPTY_THRESH_NEGATE_VAL-2; + end + else begin + prog_empty_actual_thresh_assert = C_PROG_EMPTY_THRESH_ASSERT_VAL; + prog_empty_actual_thresh_negate = C_PROG_EMPTY_THRESH_NEGATE_VAL; + end + + //Single Programmable Empty Constant Threshold + end else if (C_PROG_EMPTY_TYPE==3) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_empty_actual_thresh_assert = PROG_EMPTY_THRESH-2; + prog_empty_actual_thresh_negate = PROG_EMPTY_THRESH-2; + end + else begin + prog_empty_actual_thresh_assert = PROG_EMPTY_THRESH; + prog_empty_actual_thresh_negate = PROG_EMPTY_THRESH; + + end + //Two Programmable Empty Constant Thresholds + end else if (C_PROG_EMPTY_TYPE==4) begin + if (C_PRELOAD_REGS==1 && C_PRELOAD_LATENCY==0) begin + prog_empty_actual_thresh_assert = PROG_EMPTY_THRESH_ASSERT-2; + prog_empty_actual_thresh_negate = PROG_EMPTY_THRESH_NEGATE-2; + end + else begin + prog_empty_actual_thresh_assert = PROG_EMPTY_THRESH_ASSERT; + prog_empty_actual_thresh_negate = PROG_EMPTY_THRESH_NEGATE; + end + end + + if ((num_read_words_pe/C_DEPTH_RATIO_WR == prog_empty_actual_thresh_assert+1) + && RD_EN) begin + prog_empty_d <= 1'b1; + end else if (num_read_words_pe/C_DEPTH_RATIO_WR + <= prog_empty_actual_thresh_assert) begin + prog_empty_d <= 1'b1; + end else if (num_read_words_pe/C_DEPTH_RATIO_WR + > prog_empty_actual_thresh_negate) begin + prog_empty_d <= 1'b0; + end + + + ideal_prog_empty <= prog_empty_d; + num_rd_bits <= next_num_rd_bits; + wr_ptr_rdclk <= wr_ptr; + end //rd_rst_i==0 + end //always + +endmodule // fifo_generator_v4_3_bhv_ver_as + + +/******************************************************************************* + * Declaration of top-level module + ******************************************************************************/ +module fifo_generator_v4_3_bhv_ver_ss + ( + CLK, RST, SRST, DIN, WR_EN, RD_EN, + PROG_FULL_THRESH, PROG_FULL_THRESH_ASSERT, PROG_FULL_THRESH_NEGATE, + PROG_EMPTY_THRESH, PROG_EMPTY_THRESH_ASSERT, PROG_EMPTY_THRESH_NEGATE, + DOUT, FULL, ALMOST_FULL, WR_ACK, OVERFLOW, EMPTY, + ALMOST_EMPTY, VALID, UNDERFLOW, DATA_COUNT, + PROG_FULL, PROG_EMPTY + ); + +/****************************************************************************** + * Declare user parameters and their defaults + *****************************************************************************/ + parameter C_COMMON_CLOCK = 0; + parameter C_COUNT_TYPE = 0; + parameter C_DATA_COUNT_WIDTH = 2; + parameter C_DEFAULT_VALUE = ""; + parameter C_DIN_WIDTH = 8; + parameter C_DOUT_RST_VAL = ""; + parameter C_DOUT_WIDTH = 8; + parameter C_ENABLE_RLOCS = 0; + parameter C_FAMILY = "virtex2"; //Not allowed in Verilog model + parameter C_HAS_ALMOST_EMPTY = 0; + parameter C_HAS_ALMOST_FULL = 0; + parameter C_HAS_BACKUP = 0; + parameter C_HAS_DATA_COUNT = 0; + parameter C_HAS_MEMINIT_FILE = 0; + parameter C_HAS_OVERFLOW = 0; + parameter C_HAS_RD_DATA_COUNT = 0; + parameter C_HAS_RD_RST = 0; + parameter C_HAS_RST = 0; + parameter C_HAS_SRST = 0; + parameter C_HAS_UNDERFLOW = 0; + parameter C_HAS_VALID = 0; + parameter C_HAS_WR_ACK = 0; + parameter C_HAS_WR_DATA_COUNT = 0; + parameter C_HAS_WR_RST = 0; + parameter C_IMPLEMENTATION_TYPE = 0; + parameter C_INIT_WR_PNTR_VAL = 0; + parameter C_MEMORY_TYPE = 1; + parameter C_MIF_FILE_NAME = ""; + parameter C_OPTIMIZATION_MODE = 0; + parameter C_OVERFLOW_LOW = 0; + parameter C_PRELOAD_LATENCY = 1; + parameter C_PRELOAD_REGS = 0; + parameter C_PROG_EMPTY_THRESH_ASSERT_VAL = 0; + parameter C_PROG_EMPTY_THRESH_NEGATE_VAL = 0; + parameter C_PROG_EMPTY_TYPE = 0; + parameter C_PROG_FULL_THRESH_ASSERT_VAL = 0; + parameter C_PROG_FULL_THRESH_NEGATE_VAL = 0; + parameter C_PROG_FULL_TYPE = 0; + parameter C_RD_DATA_COUNT_WIDTH = 2; + parameter C_RD_DEPTH = 256; + parameter C_RD_PNTR_WIDTH = 8; + parameter C_UNDERFLOW_LOW = 0; + parameter C_VALID_LOW = 0; + parameter C_WR_ACK_LOW = 0; + parameter C_WR_DATA_COUNT_WIDTH = 2; + parameter C_WR_DEPTH = 256; + parameter C_WR_PNTR_WIDTH = 8; + parameter C_WR_RESPONSE_LATENCY = 1; + parameter C_FULL_FLAGS_RST_VAL = 1; + parameter C_USE_EMBEDDED_REG = 0; + + +/****************************************************************************** + * Declare Input and Output Ports + *****************************************************************************/ + input CLK; + input [C_DIN_WIDTH-1:0] DIN; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_ASSERT; + input [C_RD_PNTR_WIDTH-1:0] PROG_EMPTY_THRESH_NEGATE; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_ASSERT; + input [C_WR_PNTR_WIDTH-1:0] PROG_FULL_THRESH_NEGATE; + input RD_EN; + input RST; + input SRST; + input WR_EN; + output ALMOST_EMPTY; + output ALMOST_FULL; + output [C_DATA_COUNT_WIDTH-1:0] DATA_COUNT; + output [C_DOUT_WIDTH-1:0] DOUT; + output EMPTY; + output FULL; + output OVERFLOW; + output PROG_EMPTY; + output PROG_FULL; + output VALID; + output UNDERFLOW; + output WR_ACK; + +/******************************************************************************* + * Input and output register declarations + ******************************************************************************/ +/******************************************************************************* + * Parameters used as constants + ******************************************************************************/ + //When RST is present, set FULL reset value to '1'. + //If core has no RST, make sure FULL powers-on as '0'. + //The reset value assignments for FULL, ALMOST_FULL, and PROG_FULL are not + //changed for v3.2(IP2_Im). When the core has Sync Reset, C_HAS_SRST=1 and C_HAS_RST=0. + // Therefore, during SRST, all the FULL flags reset to 0. + parameter C_HAS_FAST_FIFO = 0; + parameter C_FIFO_WR_DEPTH = (C_COMMON_CLOCK) ? C_WR_DEPTH : C_WR_DEPTH - 1; + parameter C_FIFO_RD_DEPTH = (C_COMMON_CLOCK) ? C_RD_DEPTH : C_RD_DEPTH - 1; + + /**************************************************************************** + * Internal Registers and wires + ***************************************************************************/ + wire wr_ack_i; + wire overflow_i; + wire underflow_i; + wire valid_i; + wire valid_out; + reg valid_d1; + wire srst_i; + /******************************************************************************* + * Internal registers and wires for internal reset logics + ******************************************************************************/ + reg rst_asreg =0; + reg rst_asreg_d1 =0; + reg rst_asreg_d2 =0; + reg rst_reg =0; + reg rst_d1 =0; + wire rst_comb; + wire rst_i; + + + //Memory which will be used to simulate a FIFO + reg [C_DIN_WIDTH-1:0] memory[C_WR_DEPTH-1:0]; + reg [31:0] num_bits; + reg [31:0] wr_ptr; + reg [31:0] rd_ptr; + wire [31:0] num_read_words = num_bits/C_DOUT_WIDTH; + reg [31:0] num_read_words_q; + wire [31:0] num_write_words = num_bits/C_DIN_WIDTH; + reg [31:0] num_write_words_q; + //Removed power_on_timer in v3.2 (IP2_Im). For all reset types (Async, Sync, or no reset), the power-on values of the flags in the core are modified so that the core is ready to use from the very first clock cycle. + //reg [3:0] power_on_timer; + + //Special ideal FIFO signals + reg [C_DOUT_WIDTH-1:0] ideal_dout; + reg [C_DOUT_WIDTH-1:0] ideal_dout_d1; + wire [C_DOUT_WIDTH-1:0] ideal_dout_out; + reg ideal_wr_ack; + reg ideal_valid; + reg ideal_overflow; + reg ideal_underflow; + reg ideal_full; + reg ideal_empty; + reg ideal_almost_full; + reg ideal_almost_empty; + reg ideal_prog_full; + reg ideal_prog_empty; + + + //MSBs of the counts + wire [C_DATA_COUNT_WIDTH-1:0] ideal_d_count; + + //user specified value for reseting the size of the fifo + reg [C_DOUT_WIDTH-1:0] dout_reset_val; + + + //temporary registers for WR_RESPONSE_LATENCY feature + reg ideal_wr_ack_q; + reg ideal_overflow_q; + + reg prog_full_d; + reg prog_empty_d; + + //Delayed version of RST + reg rst_q; + reg rst_qq; + + /**************************************************************************** + * Function Declarations + ***************************************************************************/ + task write_fifo; + begin + memory[wr_ptr] <= DIN; + if (wr_ptr == 0) begin + wr_ptr <= C_WR_DEPTH - 1; + end else begin + wr_ptr <= wr_ptr - 1; + end + end + endtask // write_fifo + + task read_fifo; + begin + ideal_dout <= memory[rd_ptr]; + if (rd_ptr == 0) begin + rd_ptr <= C_RD_DEPTH - 1; + end else begin + rd_ptr <= rd_ptr - 1; + end + end + endtask + + /**************************************************************************** + * log2_val + * Returns the 'log2' value for the input value for the supported ratios + ***************************************************************************/ + function [31:0] log2_val; + input [31:0] binary_val; + + begin + if (binary_val == 8) begin + log2_val = 3; + end else if (binary_val == 4) begin + log2_val = 2; + end else begin + log2_val = 1; + end + end + endfunction + + /**************************************************************************** + * hexstr_conv + * Converts a string of type hex to a binary value (for C_DOUT_RST_VAL) + ***************************************************************************/ + function [C_DOUT_WIDTH-1:0] hexstr_conv; + input [(C_DOUT_WIDTH*8)-1:0] def_data; + + integer index,i,j; + reg [3:0] bin; + + begin + index = 0; + hexstr_conv = 'b0; + for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 ) + begin + case (def_data[7:0]) + 8'b00000000 : + begin + bin = 4'b0000; + i = -1; + end + 8'b00110000 : bin = 4'b0000; + 8'b00110001 : bin = 4'b0001; + 8'b00110010 : bin = 4'b0010; + 8'b00110011 : bin = 4'b0011; + 8'b00110100 : bin = 4'b0100; + 8'b00110101 : bin = 4'b0101; + 8'b00110110 : bin = 4'b0110; + 8'b00110111 : bin = 4'b0111; + 8'b00111000 : bin = 4'b1000; + 8'b00111001 : bin = 4'b1001; + 8'b01000001 : bin = 4'b1010; + 8'b01000010 : bin = 4'b1011; + 8'b01000011 : bin = 4'b1100; + 8'b01000100 : bin = 4'b1101; + 8'b01000101 : bin = 4'b1110; + 8'b01000110 : bin = 4'b1111; + 8'b01100001 : bin = 4'b1010; + 8'b01100010 : bin = 4'b1011; + 8'b01100011 : bin = 4'b1100; + 8'b01100100 : bin = 4'b1101; + 8'b01100101 : bin = 4'b1110; + 8'b01100110 : bin = 4'b1111; + default : + begin + bin = 4'bx; + end + endcase + for( j=0; j<4; j=j+1) + begin + if ((index*4)+j < C_DOUT_WIDTH) + begin + hexstr_conv[(index*4)+j] = bin[j]; + end + end + index = index + 1; + def_data = def_data >> 8; + end + end + endfunction + + /***************************************************************************** + * Initialize Signals + ****************************************************************************/ + initial begin + num_bits = 0; + num_read_words_q = 0; + num_write_words_q = 0; + rd_ptr = C_RD_DEPTH -1; + wr_ptr = C_WR_DEPTH -1; + dout_reset_val = hexstr_conv(C_DOUT_RST_VAL); + ideal_dout = dout_reset_val; + ideal_wr_ack = 1'b0; + ideal_valid = 1'b0; + valid_d1 = 1'b0; + ideal_overflow = 1'b0; + ideal_underflow = 1'b0; + //Modified the start-up value of FULL to '0' in v3.2 (IP2_Im) + //ideal_full = C_FULL_RESET_VAL; //was in v3.1 + ideal_full = 1'b0; //v3.2 + ideal_empty = 1'b1; + //Modified the start-up value of ALMOST_FULL to '0' in v3.2 (IP2_Im) + //ideal_almost_full = C_ALMOST_FULL_RESET_VAL; //was in v3.1 + ideal_almost_full = 1'b0; + ideal_almost_empty = 1'b1; + //Modified the start-up value of PROG_FULL to '0' in v3.2 (IP2_Im) + //ideal_prog_full = C_PROG_FULL_RESET_VAL; //was in v3.1 + ideal_prog_full = 1'b0; //v3.2 + ideal_prog_empty = 1'b1; + + //Modified the start-up value of PROG_FULL to '0' in v3.2 (IP2_Im) + //Therefore, prog_full_d is also changed + //prog_full_d = C_PROG_FULL_RESET_VAL; //was in v3.1 + prog_full_d = 1'b0; //v3.2 + prog_empty_d = 1'b1; + + //Removed in v3.2 + //power_on_timer = C_HAS_RST ? 4'h3 : 4'h0; + + //Added these initial values in v3.2 to make it consistent with the synchronization flop stages in the core. + rst_q = 1'b0; + rst_qq = 1'b0; + end + + + /***************************************************************************** + * Assign Internal ideal signals to output ports + ****************************************************************************/ + assign ideal_dout_out= (C_USE_EMBEDDED_REG==1 && + (C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))? + ideal_dout_d1: ideal_dout; + assign DOUT = ideal_dout_out; + //was in v3.1 + //assign FULL = (power_on_timer) ? C_FULL_RESET_VAL : ideal_full; + //v3.2 + assign FULL = ideal_full; + + assign EMPTY = ideal_empty; + //was in v3.1 + //assign ALMOST_FULL = (power_on_timer) ? C_ALMOST_FULL_RESET_VAL : ideal_almost_full; + //v3.2 + assign ALMOST_FULL = ideal_almost_full; + + assign ALMOST_EMPTY = ideal_almost_empty; + + assign ideal_d_count = num_read_words[C_RD_PNTR_WIDTH-1:C_RD_PNTR_WIDTH-C_DATA_COUNT_WIDTH]; + assign DATA_COUNT = ideal_d_count; + + //was in v3.1 + //assign PROG_FULL = (power_on_timer) ? C_PROG_FULL_RESET_VAL : ideal_prog_full; + //v3.2 + assign PROG_FULL = ideal_prog_full; + + assign PROG_EMPTY = ideal_prog_empty; + + //Handshaking signals can be active low, depending on _LOW parameters + assign valid_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & ~EMPTY) : ideal_valid; + assign VALID = valid_out ? !C_VALID_LOW : C_VALID_LOW; + assign valid_out = (C_PRELOAD_LATENCY==2 && + (C_MEMORY_TYPE==0 || C_MEMORY_TYPE==1))? + valid_d1: valid_i; + assign underflow_i = (C_PRELOAD_LATENCY==0) ? (RD_EN & EMPTY) : ideal_underflow; + assign UNDERFLOW = underflow_i ? !C_UNDERFLOW_LOW : C_UNDERFLOW_LOW; + + assign WR_ACK = wr_ack_i ? !C_WR_ACK_LOW : C_WR_ACK_LOW; + assign wr_ack_i = (C_WR_RESPONSE_LATENCY==2) ? ideal_wr_ack_q : + (C_WR_RESPONSE_LATENCY==1) ? ideal_wr_ack : + (WR_EN & !FULL); + assign OVERFLOW = overflow_i ? !C_OVERFLOW_LOW : C_OVERFLOW_LOW; + assign overflow_i = (C_WR_RESPONSE_LATENCY==2) ? ideal_overflow_q : + (C_WR_RESPONSE_LATENCY==1) ? ideal_overflow : + (WR_EN & FULL); + + assign srst_i = C_HAS_SRST ? SRST : 0; + + /******************************************************************************* + * Internal reset logics + ******************************************************************************/ + assign rst_comb = !rst_asreg_d2 && rst_asreg; + assign rst_i = C_HAS_RST ? rst_reg : 0; + + always @(posedge CLK or posedge rst_i) begin + if (rst_i == 1'b1) begin + valid_d1 <= 1'b0; + end else begin + if (srst_i) begin + valid_d1 <= 1'b0; + end else begin + valid_d1 <= valid_i; + end + end + end + always @(posedge CLK or posedge rst_i) begin + if (rst_i == 1'b1) begin + ideal_dout_d1 <= dout_reset_val; + end else begin + if (srst_i) begin + ideal_dout_d1 <= dout_reset_val; + end else begin + ideal_dout_d1 <= ideal_dout; + end + end + end + + always @(posedge CLK or posedge RST) begin + if (RST == 1'b1) begin + rst_asreg <= 1'b1; + end else begin + if (rst_asreg_d1 == 1'b1) begin + rst_asreg <= 1'b0; + end else begin + rst_asreg <= rst_asreg; + end + end + end + + always @(posedge CLK) begin + rst_asreg_d1 <= rst_asreg; + rst_asreg_d2 <= rst_asreg_d1; + end + + always @(posedge CLK or posedge rst_comb) begin + if (rst_comb == 1'b1) begin + rst_reg <= 1'b1; + end else begin + rst_reg <= 1'b0; + end + end + + + /******************************************************************************* + * Write and Read Logics + ******************************************************************************/ + + always @(posedge CLK or posedge rst_i) + begin : gen_wr_ack_resp + + //Register reset + rst_q <= rst_i; + rst_qq <= rst_q; + + //Register output signals to achieve desired WR_RESPONSE latency + if (C_WR_RESPONSE_LATENCY == 2) begin + if (rst_i == 1) begin + ideal_wr_ack_q <= 0; + ideal_overflow_q <= 0; + end else begin + ideal_wr_ack_q <= ideal_wr_ack; + ideal_overflow_q <= ideal_overflow; + end + end + + //Removed in v3.2 + /* + if (rst_i == 1) begin + power_on_timer <= 0; + end else if (power_on_timer > 0) begin + power_on_timer <= power_on_timer -1; + end else begin + power_on_timer <= 0; + end + */ + end // block: gen_wr_ack_resp + + // block memory has a synchronous reset + always @(posedge CLK) begin : gen_fifo_blkmemdout + //Changed the latency of during async reset to '1' instead of '2' to make it consistent with the core. + //if (rst_i || rst_q || rst_qq) begin //was in v3.1 + if (rst_i || rst_q || srst_i) begin //v3.2 + /******Initialize Read Domain Signals************************************/ + if (C_MEMORY_TYPE == 1) begin + ideal_dout <= dout_reset_val; + end + //v3.2 + //end else begin + //if (C_MEMORY_TYPE == 1 && power_on_timer >= 2) begin //was in v3.1 + // if (C_MEMORY_TYPE == 1) begin //v3.2 + // ideal_dout <= dout_reset_val; + // end + end + end + + always @(posedge CLK or posedge rst_i) begin : gen_fifo + + /****** Reset fifo - Asynchronous Reset*************************************/ + //Changed the latency of during async reset to '1' instead of '2' to make it consistent with the core. + //if (rst_i || rst_q || rst_qq) begin //was in v3.1 + //if (rst_i || rst_q) begin //v3.2 + if (rst_i ) begin //v3.2 + /******Initialize Generic FIFO constructs********************************/ + num_bits <= 0; + wr_ptr <= C_WR_DEPTH - 1; + rd_ptr <= C_RD_DEPTH - 1; + num_read_words_q <= 0; + num_write_words_q <= 0; + + + /******Initialize Write Domain Signals***********************************/ + ideal_wr_ack <= 0; + ideal_full <= C_FULL_FLAGS_RST_VAL; + ideal_almost_full <= C_FULL_FLAGS_RST_VAL; + + /******Initialize Read Domain Signals************************************/ + if (C_MEMORY_TYPE != 1) begin + ideal_dout <= dout_reset_val; + end + ideal_valid <= 1'b0; + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + end else begin + if (srst_i) begin + // SRST is available only for Sync BRAM and Sync DRAM. Not for SSHFT. + if (C_MEMORY_TYPE == 1 || C_MEMORY_TYPE == 2) begin + /******Initialize Generic FIFO constructs********************************/ + num_bits <= 0; + wr_ptr <= C_WR_DEPTH - 1; + rd_ptr <= C_RD_DEPTH - 1; + num_read_words_q <= 0; + num_write_words_q <= 0; + + /******Initialize Write Domain Signals***********************************/ + ideal_wr_ack <= 0; + ideal_full <= 0; //'0' + ideal_almost_full <= 0; //'0' + + /******Initialize Read Domain Signals************************************/ + //Reset DOUT of Sync DRAM. Sync BRAM DOUT was reset in the above always block. + if (C_MEMORY_TYPE == 2) begin + ideal_dout <= dout_reset_val; + end + ideal_valid <= 1'b0; + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + end + + end else begin //normal operating conditions + /**********************************************************************/ + // Synchronous FIFO Condition #1 : Writing and not reading + /**********************************************************************/ + if (WR_EN & ~RD_EN) begin + + /*********************************/ + //If the FIFO is full, do NOT perform the write, + // update flags accordingly + /*********************************/ + if (num_write_words >= C_FIFO_WR_DEPTH) begin + ideal_wr_ack <= 0; + + //still full + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + //write unsuccessful - do not change contents + + // no read attempted + ideal_valid <= 1'b0; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + + /*********************************/ + //If the FIFO is reporting FULL + // (Startup condition) + /*********************************/ + end else if ((num_write_words < C_FIFO_WR_DEPTH) && (ideal_full == 1'b1)) begin + ideal_wr_ack <= 0; + + //still full + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //write unsuccessful - do not change contents + + // no read attempted + ideal_valid <= 1'b0; + + //FIFO EMPTY in this state can not be determined + //ideal_empty <= 1'b0; + //ideal_almost_empty <= 1'b0; + + + /*********************************/ + //If the FIFO is one from full + /*********************************/ + end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin + //good write + ideal_wr_ack <= 1; + + //FIFO is one from FULL and going FULL + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + //Add input data + write_fifo; + + // no read attempted + ideal_valid <= 1'b0; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + num_bits <= num_bits + C_DIN_WIDTH; + + /*********************************/ + //If the FIFO is 2 from full + /*********************************/ + end else if (num_write_words == C_FIFO_WR_DEPTH-2) begin + //good write + ideal_wr_ack <= 1; + + //2 from full, and writing, so set almost_full + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + //Add input data + write_fifo; + + //no read attempted + ideal_valid <= 1'b0; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + num_bits <= num_bits + C_DIN_WIDTH; + + /*********************************/ + //If the FIFO is ALMOST EMPTY + /*********************************/ + end else if (num_read_words == 1) begin + //good write + ideal_wr_ack <= 1; + + //Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Add input data + write_fifo; + + // no read attempted + ideal_valid <= 1'b0; + + //Leaving ALMOST_EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + num_bits <= num_bits + C_DIN_WIDTH; + + /*********************************/ + //If the FIFO is EMPTY + /*********************************/ + end else if (num_read_words == 0) begin + // good write + ideal_wr_ack <= 1; + + //Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Add input data + write_fifo; + + // no read attempted + ideal_valid <= 1'b0; + + //Leaving EMPTY (still ALMOST_EMPTY) + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + num_bits <= num_bits + C_DIN_WIDTH; + + /*********************************/ + //If the FIFO is not near EMPTY or FULL + /*********************************/ + end else begin + // good write + ideal_wr_ack <= 1; + + //Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Add input data + write_fifo; + + // no read attempted + ideal_valid <= 1'b0; + + //Not near EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + num_bits <= num_bits + C_DIN_WIDTH; + + end // average case + + + /**********************************************************************/ + // Synchronous FIFO Condition #2 : Reading and not writing + /**********************************************************************/ + end else if (~WR_EN & RD_EN) begin + + /*********************************/ + //If the FIFO is EMPTY + /*********************************/ + if ((num_read_words == 0) || (ideal_empty == 1'b1)) begin + //no write attemped + ideal_wr_ack <= 0; + + //FIFO is not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read will fail + ideal_valid <= 1'b0; + + //FIFO is still empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + //No read + + /*********************************/ + //If the FIFO is ALMOST EMPTY + /*********************************/ + end else if (num_read_words == 1) begin + //no write attempted + ideal_wr_ack <= 0; + + //FIFO is not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read successful + ideal_valid <= 1'b1; + + //This read will make FIFO go empty + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + //Get the data from the FIFO + read_fifo; + num_bits <= num_bits - C_DIN_WIDTH; + + + /*********************************/ + //If the FIFO is 2 from EMPTY + /*********************************/ + end else if (num_read_words == 2) begin + + //no write attempted + ideal_wr_ack <= 0; + + //FIFO is not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read successful + ideal_valid <= 1'b1; + + //FIFO is going ALMOST_EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + //Get the data from the FIFO + read_fifo; + num_bits <= num_bits - C_DOUT_WIDTH; + + + + /*********************************/ + //If the FIFO is one from full + /*********************************/ + end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin + + //no write attempted + ideal_wr_ack <= 0; + + //FIFO is leaving ALMOST FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read successful + ideal_valid <= 1'b1; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits - C_DOUT_WIDTH; + + + /*********************************/ + // FIFO is FULL + /*********************************/ + end else if (num_write_words >= C_FIFO_WR_DEPTH) + begin + //no write attempted + ideal_wr_ack <= 0; + + //FIFO is leaving FULL, but is still ALMOST_FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + //Read successful + ideal_valid <= 1'b1; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits - C_DOUT_WIDTH; + + /*********************************/ + //If the FIFO is not near EMPTY or FULL + /*********************************/ + end else begin + //no write attemped + ideal_wr_ack <= 0; + + //Not near empty + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read successful + ideal_valid <= 1'b1; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits - C_DOUT_WIDTH; + + + end // average read + + + /**********************************************************************/ + // Synchronous FIFO Condition #3 : Reading and writing + /**********************************************************************/ + end else if (WR_EN & RD_EN) begin + + /*********************************/ + // FIFO is FULL + /*********************************/ + if (num_write_words >= C_FIFO_WR_DEPTH) begin + + ideal_wr_ack <= 0; + + //Read will be successful, so FIFO will leave FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + //Read successful + ideal_valid <= 1'b1; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits - C_DOUT_WIDTH; + + + /*********************************/ + // FIFO is reporting FULL, but it is empty + // (This is a special case, when coming out of RST + /*********************************/ + end else if ((num_write_words == 0) && (ideal_full == 1'b1)) begin + + ideal_wr_ack <= 0; + + //Read will be successful, so FIFO will leave FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //Read unsuccessful + ideal_valid <= 1'b0; + + //Report empty condition + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + //Do not read from empty FIFO + // Read from the FIFO + + + /*********************************/ + //If the FIFO is one from full + /*********************************/ + end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin + + //Write successful + ideal_wr_ack <= 1; + + //FIFO will remain ALMOST_FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + // put the data into the FIFO + write_fifo; + + //Read successful + ideal_valid <= 1'b1; + + //Not near empty + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits + C_DIN_WIDTH - C_DOUT_WIDTH; + + /*********************************/ + //If the FIFO is ALMOST EMPTY + /*********************************/ + end else if (num_read_words == 1) begin + + //Write successful + ideal_wr_ack <= 1; + + // Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + // put the data into the FIFO + write_fifo; + + //Read successful + ideal_valid <= 1'b1; + + //FIFO will stay ALMOST_EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits + C_DIN_WIDTH - C_DOUT_WIDTH; + + + /*********************************/ + //If the FIFO is EMPTY + /*********************************/ + end else if (num_read_words == 0) begin + + //Write successful + ideal_wr_ack <= 1; + + // Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + // put the data into the FIFO + write_fifo; + + //Read will fail + ideal_valid <= 1'b0; + + //FIFO will leave EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + // No read + num_bits <= num_bits + C_DIN_WIDTH; + + + /*********************************/ + //If the FIFO is not near EMPTY or FULL + /*********************************/ + end else begin + + //Write successful + ideal_wr_ack <= 1; + + // Not near FULL + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + // put the data into the FIFO + write_fifo; + + //Read successful + ideal_valid <= 1'b1; + + // Not near EMPTY + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //Read from the FIFO + read_fifo; + num_bits <= num_bits + C_DIN_WIDTH - C_DOUT_WIDTH; + + end // average case + + /**********************************************************************/ + // Synchronous FIFO Condition #4 : Not reading or writing + /*** + *******************************************************************/ + end else begin + + /*********************************/ + // FIFO is FULL + /*********************************/ + if (num_write_words >= C_FIFO_WR_DEPTH) begin + + //No write + ideal_wr_ack <= 0; + ideal_full <= 1'b1; + ideal_almost_full <= 1'b1; + + //No read + ideal_valid <= 1'b0; + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //No change to memory + + /*********************************/ + //If the FIFO is one from full + /*********************************/ + end else if (num_write_words == C_FIFO_WR_DEPTH-1) begin + + //No write + ideal_wr_ack <= 0; + ideal_full <= 1'b0; + ideal_almost_full <= 1'b1; + + //No read + ideal_valid <= 1'b0; + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //No change to memory + + /*********************************/ + //If the FIFO is ALMOST EMPTY + /*********************************/ + end else if (num_read_words == 1) begin + //No write + ideal_wr_ack <= 0; + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //No read + ideal_valid <= 1'b0; + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b1; + + //No change to memory + + end // almost empty + + + /*********************************/ + //If the FIFO is EMPTY + /*********************************/ + else if (num_read_words == 0) + begin + //No write + ideal_wr_ack <= 0; + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //No read + ideal_valid <= 1'b0; + ideal_empty <= 1'b1; + ideal_almost_empty <= 1'b1; + + //No change to memory + + /*********************************/ + //If the FIFO is not near EMPTY or FULL + /*********************************/ + end else begin + + //No write + ideal_wr_ack <= 0; + ideal_full <= 1'b0; + ideal_almost_full <= 1'b0; + + //No read + ideal_valid <= 1'b0; + ideal_empty <= 1'b0; + ideal_almost_empty <= 1'b0; + + //No change to memory + + end // average case + + end // neither reading or writing + + num_read_words_q <= num_read_words; + num_write_words_q <= num_write_words; + + end //normal operating conditions + end + + end // block: gen_fifo + + //Generate overflow and underflow flags seperately + //because they don't support async rst + always @(posedge CLK) begin + ideal_overflow <= WR_EN & ideal_full; + ideal_underflow <= ideal_empty & RD_EN; + end + + always @(posedge CLK or posedge rst_i) begin : gen_fifo_p + + /****** Reset fifo - Async Reset****************************************/ + //The latency of de-assertion of the flags is reduced by 1 to be consistent with the core. + //if (rst_i || rst_q) begin //was in v3.1 + if (rst_i) begin //v3.2 + ideal_prog_full <= C_FULL_FLAGS_RST_VAL; + ideal_prog_empty <= 1'b1; + prog_full_d <= C_FULL_FLAGS_RST_VAL; + prog_empty_d <= 1'b1; + + end else begin + if (srst_i) begin + //SRST is available only for Sync BRAM and Sync DRAM. Not for SSHFT. + if (C_MEMORY_TYPE == 1 || C_MEMORY_TYPE == 2) begin + ideal_prog_full <= 1'b0; + ideal_prog_empty <= 1'b1; + prog_full_d <= 1'b0; + prog_empty_d <= 1'b1; + end + end else begin + + /***************************************************************** + * Programmable FULL flags + ****************************************************************/ + //Single constant threshold + if (C_PROG_FULL_TYPE == 1) begin + if ((num_write_words >= C_PROG_FULL_THRESH_ASSERT_VAL-1) + && WR_EN && !RD_EN) begin + prog_full_d <= 1'b1; + end else if (((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL) + && RD_EN && !WR_EN) || (rst_q && !rst_i)) begin //v3.2 + prog_full_d <= 1'b0; + end + + //Dual constant thresholds + end else if (C_PROG_FULL_TYPE == 2) begin + if ((num_write_words == C_PROG_FULL_THRESH_ASSERT_VAL-1) + && WR_EN && !RD_EN) begin + prog_full_d <= 1'b1; + end else if ((num_write_words == C_PROG_FULL_THRESH_NEGATE_VAL) + && RD_EN && !WR_EN) begin + prog_full_d <= 1'b0; + end + + //Single input threshold + end else if (C_PROG_FULL_TYPE == 3) begin + if ((num_write_words == PROG_FULL_THRESH-1) + && WR_EN && !RD_EN) begin + prog_full_d <= 1'b1; + end else if ((num_write_words == PROG_FULL_THRESH) + && !WR_EN && RD_EN) begin + prog_full_d <= 1'b0; + end else if (num_write_words >= PROG_FULL_THRESH) begin + prog_full_d <= 1'b1; + end else if (num_write_words < PROG_FULL_THRESH) begin + prog_full_d <= 1'b0; + end + + //Dual input thresholds + end else begin + if ((num_write_words == PROG_FULL_THRESH_ASSERT-1) + && WR_EN && !RD_EN) begin + prog_full_d <= 1'b1; + end else if ((num_write_words == PROG_FULL_THRESH_NEGATE) + && !WR_EN && RD_EN)begin + prog_full_d <= 1'b0; + end else if (num_write_words >= PROG_FULL_THRESH_ASSERT) begin + prog_full_d <= 1'b1; + end else if (num_write_words < PROG_FULL_THRESH_NEGATE) begin + prog_full_d <= 1'b0; + end + end + + /***************************************************************** + * Programmable EMPTY flags + ****************************************************************/ + //Single constant threshold + if (C_PROG_EMPTY_TYPE == 1) begin + if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1) + && RD_EN && !WR_EN) begin + prog_empty_d <= 1'b1; + end else if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL) + && WR_EN && !RD_EN) begin + prog_empty_d <= 1'b0; + end + //Dual constant thresholds + end else if (C_PROG_EMPTY_TYPE == 2) begin + if ((num_read_words == C_PROG_EMPTY_THRESH_ASSERT_VAL+1) + && RD_EN && !WR_EN) begin + prog_empty_d <= 1'b1; + end else if ((num_read_words == C_PROG_EMPTY_THRESH_NEGATE_VAL) + && !RD_EN && WR_EN) begin + prog_empty_d <= 1'b0; + end + + //Single input threshold + end else if (C_PROG_EMPTY_TYPE == 3) begin + if ((num_read_words == PROG_EMPTY_THRESH+1) + && RD_EN && !WR_EN) begin + prog_empty_d <= 1'b1; + end else if ((num_read_words == PROG_EMPTY_THRESH) + && !RD_EN && WR_EN) begin + prog_empty_d <= 1'b0; + end else if (num_read_words <= PROG_EMPTY_THRESH) begin + prog_empty_d <= 1'b1; + end else if (num_read_words > PROG_EMPTY_THRESH)begin + prog_empty_d <= 1'b0; + end + + //Dual input thresholds + end else begin + if (num_read_words <= PROG_EMPTY_THRESH_ASSERT) begin + prog_empty_d <= 1'b1; + end else if ((num_read_words == PROG_EMPTY_THRESH_ASSERT+1) + && RD_EN && !WR_EN) begin + prog_empty_d <= 1'b1; + end else if (num_read_words > PROG_EMPTY_THRESH_NEGATE)begin + prog_empty_d <= 1'b0; + end else if ((num_read_words == PROG_EMPTY_THRESH_NEGATE) + && !RD_EN && WR_EN) begin + prog_empty_d <= 1'b0; + end + end + + ideal_prog_empty <= prog_empty_d; + if (rst_q && !rst_i) begin + ideal_prog_full <= 1'b0; + end else begin + ideal_prog_full <= prog_full_d; + end + + end //if (srst_i) begin + end //if (rst_i) begin + end //always @(posedge CLK or posedge rst_i) begin : gen_fifo_p +endmodule // fifo_generator_v4_3_bhv_ver_ss + + +module fifo_generator_v4_3_bhv_ver_preload0 + ( + RD_CLK, + RD_RST, + RD_EN, + FIFOEMPTY, + FIFODATA, + USERDATA, + USERVALID, + USERUNDERFLOW, + USEREMPTY, + USERALMOSTEMPTY, + RAMVALID, + FIFORDEN + ); + + + parameter C_DOUT_RST_VAL = ""; + parameter C_DOUT_WIDTH = 8; + parameter C_HAS_RST = 0; + parameter C_USERVALID_LOW = 0; + parameter C_USERUNDERFLOW_LOW = 0; + + + input RD_CLK; + input RD_RST; + input RD_EN; + input FIFOEMPTY; + input [C_DOUT_WIDTH-1:0] FIFODATA; + output [C_DOUT_WIDTH-1:0] USERDATA; + output USERVALID; + output USERUNDERFLOW; + output USEREMPTY; + output USERALMOSTEMPTY; + output RAMVALID; + output FIFORDEN; + + wire RD_CLK; + wire RD_RST; + wire RD_EN; + wire FIFOEMPTY; + wire [C_DOUT_WIDTH-1:0] FIFODATA; + reg [C_DOUT_WIDTH-1:0] USERDATA; + wire USERVALID; + wire USERUNDERFLOW; + wire USEREMPTY; + wire USERALMOSTEMPTY; + wire RAMVALID; + wire FIFORDEN; + + wire preloadstage1; + wire preloadstage2; + reg ram_valid_i; + reg read_data_valid_i; + wire ram_regout_en; + wire ram_rd_en; + reg empty_i = 1'b1; + reg empty_q = 1'b1; + reg rd_en_q = 1'b0; //Fix for CR:236270 in v3.2 //prasanna + reg almost_empty_i = 1'b1; + reg almost_empty_q = 1'b1; + wire rd_rst_i; + + +/************************************************************************* +* FUNCTIONS +*************************************************************************/ + + /************************************************************************* + * hexstr_conv + * Converts a string of type hex to a binary value (for C_DOUT_RST_VAL) + ***********************************************************************/ + function [C_DOUT_WIDTH-1:0] hexstr_conv; + input [(C_DOUT_WIDTH*8)-1:0] def_data; + + integer index,i,j; + reg [3:0] bin; + + begin + index = 0; + hexstr_conv = 'b0; + for( i=C_DOUT_WIDTH-1; i>=0; i=i-1 ) + begin + case (def_data[7:0]) + 8'b00000000 : + begin + bin = 4'b0000; + i = -1; + end + 8'b00110000 : bin = 4'b0000; + 8'b00110001 : bin = 4'b0001; + 8'b00110010 : bin = 4'b0010; + 8'b00110011 : bin = 4'b0011; + 8'b00110100 : bin = 4'b0100; + 8'b00110101 : bin = 4'b0101; + 8'b00110110 : bin = 4'b0110; + 8'b00110111 : bin = 4'b0111; + 8'b00111000 : bin = 4'b1000; + 8'b00111001 : bin = 4'b1001; + 8'b01000001 : bin = 4'b1010; + 8'b01000010 : bin = 4'b1011; + 8'b01000011 : bin = 4'b1100; + 8'b01000100 : bin = 4'b1101; + 8'b01000101 : bin = 4'b1110; + 8'b01000110 : bin = 4'b1111; + 8'b01100001 : bin = 4'b1010; + 8'b01100010 : bin = 4'b1011; + 8'b01100011 : bin = 4'b1100; + 8'b01100100 : bin = 4'b1101; + 8'b01100101 : bin = 4'b1110; + 8'b01100110 : bin = 4'b1111; + default : + begin + bin = 4'bx; + end + endcase + for( j=0; j<4; j=j+1) + begin + if ((index*4)+j < C_DOUT_WIDTH) + begin + hexstr_conv[(index*4)+j] = bin[j]; + end + end + index = index + 1; + def_data = def_data >> 8; + end + end + endfunction + +initial + begin + ram_valid_i = 1'b0; + read_data_valid_i = 1'b0; + USERDATA = hexstr_conv(C_DOUT_RST_VAL); + end + + + //****************************************************************************** + // connect up optional reset + //****************************************************************************** + assign rd_rst_i = C_HAS_RST ? RD_RST : 0; + + + //****************************************************************************** + // preloadstage2 indicates that stage2 needs to be updated. This is true + // whenever read_data_valid is false, and RAM_valid is true. + //****************************************************************************** + assign preloadstage2 = ram_valid_i & (~read_data_valid_i | RD_EN); + + //****************************************************************************** + // preloadstage1 indicates that stage1 needs to be updated. This is true + // whenever the RAM has data (RAM_EMPTY is false), and either RAM_Valid is + // false (indicating that Stage1 needs updating), or preloadstage2 is active + // (indicating that Stage2 is going to update, so Stage1, therefore, must + // also be updated to keep it valid. + //****************************************************************************** + assign preloadstage1 = ((~ram_valid_i | preloadstage2) & ~FIFOEMPTY); + + //****************************************************************************** + // Calculate RAM_REGOUT_EN + // The output registers are controlled by the ram_regout_en signal. + // These registers should be updated either when the output in Stage2 is + // invalid (preloadstage2), OR when the user is reading, in which case the + // Stage2 value will go invalid unless it is replenished. + //****************************************************************************** + assign ram_regout_en = preloadstage2; + + //****************************************************************************** + // Calculate RAM_RD_EN + // RAM_RD_EN will be asserted whenever the RAM needs to be read in order to + // update the value in Stage1. + // One case when this happens is when preloadstage1=true, which indicates + // that the data in Stage1 or Stage2 is invalid, and needs to automatically + // be updated. + // The other case is when the user is reading from the FIFO, which guarantees + // that Stage1 or Stage2 will be invalid on the next clock cycle, unless it is + // replinished by data from the memory. So, as long as the RAM has data in it, + // a read of the RAM should occur. + //****************************************************************************** + assign ram_rd_en = (RD_EN & ~FIFOEMPTY) | preloadstage1; + + //****************************************************************************** + // Calculate RAMVALID_P0_OUT + // RAMVALID_P0_OUT indicates that the data in Stage1 is valid. + // + // If the RAM is being read from on this clock cycle (ram_rd_en=1), then + // RAMVALID_P0_OUT is certainly going to be true. + // If the RAM is not being read from, but the output registers are being + // updated to fill Stage2 (ram_regout_en=1), then Stage1 will be emptying, + // therefore causing RAMVALID_P0_OUT to be false. + // Otherwise, RAMVALID_P0_OUT will remain unchanged. + //****************************************************************************** + always @ (posedge RD_CLK or posedge rd_rst_i) + begin // PROCESS regout_valid + if (rd_rst_i) // asynchronous reset (active high) + ram_valid_i <= 1'b0; + else + begin + if (ram_rd_en == 1'b1) + ram_valid_i <= 1'b1; + else + if (ram_regout_en == 1'b1) + ram_valid_i <= 1'b0; + else + ram_valid_i <= ram_valid_i; + end //rd_rst_i + end //always + + //****************************************************************************** + // Calculate READ_DATA_VALID + // READ_DATA_VALID indicates whether the value in Stage2 is valid or not. + // Stage2 has valid data whenever Stage1 had valid data and ram_regout_en_i=1, + // such that the data in Stage1 is propogated into Stage2. + //****************************************************************************** + always @ (posedge RD_CLK or posedge rd_rst_i) + begin + if (rd_rst_i) + read_data_valid_i <= 1'b0; + else + read_data_valid_i <= ram_valid_i | (read_data_valid_i & ~RD_EN); + end //always + + + //***************************************************************************** + // Calculate EMPTY + // Defined as the inverse of READ_DATA_VALID + // + // Description: + // + // If read_data_valid_i indicates that the output is not valid, + // and there is no valid data on the output of the ram to preload it + // with, then we will report empty. + // + // If there is no valid data on the output of the ram and we are + // reading, then the FIFO will go empty. + // + //***************************************************************************** + always @ (posedge RD_CLK or posedge rd_rst_i) + begin + if (rd_rst_i) // asynchronous reset (active high) + begin + empty_i <= 1'b1; + empty_q <= 1'b1; + end + else // rising clock edge + begin + empty_i <= (~ram_valid_i & ~read_data_valid_i) | (~ram_valid_i & RD_EN); + empty_q <= empty_i; + end + end //always + + //Fix for CR:236270 //prasanna + //Register RD_EN from user to calculate USERUNDERFLOW. + always @ (posedge RD_CLK or posedge rd_rst_i) + begin + if (rd_rst_i) // asynchronous reset (active high) + begin + rd_en_q <= 1'b0; + end + else // rising clock edge + begin + rd_en_q <= RD_EN; + end + end //always + + + //***************************************************************************** + // Calculate user_almost_empty + // user_almost_empty is defined such that, unless more words are written + // to the FIFO, the next read will cause the FIFO to go EMPTY. + // + // In most cases, whenever the output registers are updated (due to a user + // read or a preload condition), then user_almost_empty will update to + // whatever RAM_EMPTY is. + // + // The exception is when the output is valid, the user is not reading, and + // Stage1 is not empty. In this condition, Stage1 will be preloaded from the + // memory, so we need to make sure user_almost_empty deasserts properly under + // this condition. + //***************************************************************************** + always @ (posedge RD_CLK or posedge rd_rst_i) + begin + if (rd_rst_i) // asynchronous reset (active high) + begin + almost_empty_i <= 1'b1; + almost_empty_q <= 1'b1; + end + else // rising clock edge + begin + if ((ram_regout_en) | (~FIFOEMPTY & read_data_valid_i & ~RD_EN)) + begin + almost_empty_i <= FIFOEMPTY; + end + almost_empty_q <= empty_i; + end + end //always + + + assign USEREMPTY = empty_i; + assign USERALMOSTEMPTY = almost_empty_i; + assign FIFORDEN = ram_rd_en; + assign RAMVALID = ram_valid_i; + assign USERVALID = C_USERVALID_LOW ? ~read_data_valid_i : read_data_valid_i; + //assign USERUNDERFLOW = C_USERUNDERFLOW_LOW ? ~(empty_q & RD_EN) : empty_q & RD_EN; //Bug in v3.1 (CR:236270) + assign USERUNDERFLOW = C_USERUNDERFLOW_LOW ? ~(empty_q & rd_en_q) : empty_q & rd_en_q; //Fix for CR:236270 in v3.2 //prasanna + + always @ (posedge RD_CLK or posedge rd_rst_i) + begin + if (rd_rst_i) // asynchronous reset (active high) + USERDATA <= hexstr_conv(C_DOUT_RST_VAL); + else // rising clock edge + if (ram_regout_en) + USERDATA <= FIFODATA; + end //always + + + + + +endmodule |