From 0df4b801a34697f2058b4a7b95e08d2a0576c9db Mon Sep 17 00:00:00 2001 From: Ben Hilburn Date: Thu, 10 Oct 2013 10:17:27 -0700 Subject: Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus. --- fpga/usrp3/lib/wishbone/i2c_master_top.v | 301 +++++++++++++++++++++++++++++++ 1 file changed, 301 insertions(+) create mode 100644 fpga/usrp3/lib/wishbone/i2c_master_top.v (limited to 'fpga/usrp3/lib/wishbone/i2c_master_top.v') diff --git a/fpga/usrp3/lib/wishbone/i2c_master_top.v b/fpga/usrp3/lib/wishbone/i2c_master_top.v new file mode 100644 index 000000000..be1fcfe55 --- /dev/null +++ b/fpga/usrp3/lib/wishbone/i2c_master_top.v @@ -0,0 +1,301 @@ +///////////////////////////////////////////////////////////////////// +//// //// +//// WISHBONE revB.2 compliant I2C Master controller Top-level //// +//// //// +//// //// +//// Author: Richard Herveille //// +//// richard@asics.ws //// +//// www.asics.ws //// +//// //// +//// Downloaded from: http://www.opencores.org/projects/i2c/ //// +//// //// +///////////////////////////////////////////////////////////////////// +//// //// +//// Copyright (C) 2001 Richard Herveille //// +//// richard@asics.ws //// +//// //// +//// This source file may be used and distributed without //// +//// restriction provided that this copyright statement is not //// +//// removed from the file and that any derivative work contains //// +//// the original copyright notice and the associated disclaimer.//// +//// //// +//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// +//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// +//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// +//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// +//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// +//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// +//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// +//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// +//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// +//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// +//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// +//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// +//// POSSIBILITY OF SUCH DAMAGE. //// +//// //// +///////////////////////////////////////////////////////////////////// + +// CVS Log +// +// $Id: i2c_master_top.v,v 1.11 2005/02/27 09:26:24 rherveille Exp $ +// +// $Date: 2005/02/27 09:26:24 $ +// $Revision: 1.11 $ +// $Author: rherveille $ +// $Locker: $ +// $State: Exp $ +// +// Change History: +// $Log: i2c_master_top.v,v $ +// Revision 1.11 2005/02/27 09:26:24 rherveille +// Fixed register overwrite issue. +// Removed full_case pragma, replaced it by a default statement. +// +// Revision 1.10 2003/09/01 10:34:38 rherveille +// Fix a blocking vs. non-blocking error in the wb_dat output mux. +// +// Revision 1.9 2003/01/09 16:44:45 rherveille +// Fixed a bug in the Command Register declaration. +// +// Revision 1.8 2002/12/26 16:05:12 rherveille +// Small code simplifications +// +// Revision 1.7 2002/12/26 15:02:32 rherveille +// Core is now a Multimaster I2C controller +// +// Revision 1.6 2002/11/30 22:24:40 rherveille +// Cleaned up code +// +// Revision 1.5 2001/11/10 10:52:55 rherveille +// Changed PRER reset value from 0x0000 to 0xffff, conform specs. +// + +// synopsys translate_off +//`include "timescale.v" +// synopsys translate_on + +`include "i2c_master_defines.v" + +module i2c_master_top( + wb_clk_i, wb_rst_i, arst_i, wb_adr_i, wb_dat_i, wb_dat_o, + wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_inta_o, + scl_pad_i, scl_pad_o, scl_padoen_o, sda_pad_i, sda_pad_o, sda_padoen_o ); + + // parameters + parameter ARST_LVL = 1'b0; // asynchronous reset level + + // + // inputs & outputs + // + + // wishbone signals + input wb_clk_i; // master clock input + input wb_rst_i; // synchronous active high reset + input arst_i; // asynchronous reset + input [2:0] wb_adr_i; // lower address bits + input [7:0] wb_dat_i; // databus input + output [7:0] wb_dat_o; // databus output + input wb_we_i; // write enable input + input wb_stb_i; // stobe/core select signal + input wb_cyc_i; // valid bus cycle input + output wb_ack_o; // bus cycle acknowledge output + output wb_inta_o; // interrupt request signal output + + reg [7:0] wb_dat_o; + reg wb_ack_o; + reg wb_inta_o; + + // I2C signals + // i2c clock line + input scl_pad_i; // SCL-line input + output scl_pad_o; // SCL-line output (always 1'b0) + output scl_padoen_o; // SCL-line output enable (active low) + + // i2c data line + input sda_pad_i; // SDA-line input + output sda_pad_o; // SDA-line output (always 1'b0) + output sda_padoen_o; // SDA-line output enable (active low) + + + // + // variable declarations + // + + // registers + reg [15:0] prer; // clock prescale register + reg [ 7:0] ctr; // control register + reg [ 7:0] txr; // transmit register + wire [ 7:0] rxr; // receive register + reg [ 7:0] cr; // command register + wire [ 7:0] sr; // status register + + // done signal: command completed, clear command register + wire done; + + // core enable signal + wire core_en; + wire ien; + + // status register signals + wire irxack; + reg rxack; // received aknowledge from slave + reg tip; // transfer in progress + reg irq_flag; // interrupt pending flag + wire i2c_busy; // bus busy (start signal detected) + wire i2c_al; // i2c bus arbitration lost + reg al; // status register arbitration lost bit + + // + // module body + // + + // generate internal reset + wire rst_i = arst_i ^ ARST_LVL; + + // generate wishbone signals + wire wb_wacc = wb_cyc_i & wb_stb_i & wb_we_i; + + // generate acknowledge output signal + always @(posedge wb_clk_i) + wb_ack_o <= #1 wb_cyc_i & wb_stb_i & ~wb_ack_o; // because timing is always honored + + // assign DAT_O + always @(posedge wb_clk_i) + begin + case (wb_adr_i) // synopsis parallel_case + 3'b000: wb_dat_o <= #1 prer[ 7:0]; + 3'b001: wb_dat_o <= #1 prer[15:8]; + 3'b010: wb_dat_o <= #1 ctr; + 3'b011: wb_dat_o <= #1 rxr; // write is transmit register (txr) + 3'b100: wb_dat_o <= #1 sr; // write is command register (cr) + 3'b101: wb_dat_o <= #1 txr; + 3'b110: wb_dat_o <= #1 cr; + 3'b111: wb_dat_o <= #1 0; // reserved + endcase + end + + // generate registers + always @(posedge wb_clk_i or negedge rst_i) + if (!rst_i) + begin + prer <= #1 16'hffff; + ctr <= #1 8'h0; + txr <= #1 8'h0; + end + else if (wb_rst_i) + begin + prer <= #1 16'hffff; + ctr <= #1 8'h0; + txr <= #1 8'h0; + end + else + if (wb_wacc) + case (wb_adr_i) // synopsis parallel_case + 3'b000 : prer [ 7:0] <= #1 wb_dat_i; + 3'b001 : prer [15:8] <= #1 wb_dat_i; + 3'b010 : ctr <= #1 wb_dat_i; + 3'b011 : txr <= #1 wb_dat_i; + default: ; + endcase + + // generate command register (special case) + always @(posedge wb_clk_i or negedge rst_i) + if (~rst_i) + cr <= #1 8'h0; + else if (wb_rst_i) + cr <= #1 8'h0; + else if (wb_wacc) + begin + if (core_en & (wb_adr_i == 3'b100) ) + cr <= #1 wb_dat_i; + end + else + begin + if (done | i2c_al) + cr[7:4] <= #1 4'h0; // clear command bits when done + // or when aribitration lost + cr[2:1] <= #1 2'b0; // reserved bits + cr[0] <= #1 2'b0; // clear IRQ_ACK bit + end + + + // decode command register + wire sta = cr[7]; + wire sto = cr[6]; + wire rd = cr[5]; + wire wr = cr[4]; + wire ack = cr[3]; + wire iack = cr[0]; + + // decode control register + assign core_en = ctr[7]; + assign ien = ctr[6]; + + // hookup byte controller block + i2c_master_byte_ctrl byte_controller ( + .clk ( wb_clk_i ), + .rst ( wb_rst_i ), + .nReset ( rst_i ), + .ena ( core_en ), + .clk_cnt ( prer ), + .start ( sta ), + .stop ( sto ), + .read ( rd ), + .write ( wr ), + .ack_in ( ack ), + .din ( txr ), + .cmd_ack ( done ), + .ack_out ( irxack ), + .dout ( rxr ), + .i2c_busy ( i2c_busy ), + .i2c_al ( i2c_al ), + .scl_i ( scl_pad_i ), + .scl_o ( scl_pad_o ), + .scl_oen ( scl_padoen_o ), + .sda_i ( sda_pad_i ), + .sda_o ( sda_pad_o ), + .sda_oen ( sda_padoen_o ) + ); + + // status register block + interrupt request signal + always @(posedge wb_clk_i or negedge rst_i) + if (!rst_i) + begin + al <= #1 1'b0; + rxack <= #1 1'b0; + tip <= #1 1'b0; + irq_flag <= #1 1'b0; + end + else if (wb_rst_i) + begin + al <= #1 1'b0; + rxack <= #1 1'b0; + tip <= #1 1'b0; + irq_flag <= #1 1'b0; + end + else + begin + al <= #1 i2c_al | (al & ~sta); + rxack <= #1 irxack; + tip <= #1 (rd | wr); + irq_flag <= #1 (done | i2c_al | irq_flag) & ~iack; // interrupt request flag is always generated + end + + // generate interrupt request signals + always @(posedge wb_clk_i or negedge rst_i) + if (!rst_i) + wb_inta_o <= #1 1'b0; + else if (wb_rst_i) + wb_inta_o <= #1 1'b0; + else + wb_inta_o <= #1 irq_flag && ien; // interrupt signal is only generated when IEN (interrupt enable bit is set) + + // assign status register bits + assign sr[7] = rxack; + assign sr[6] = i2c_busy; + assign sr[5] = al; + assign sr[4:2] = 3'h0; // reserved + assign sr[1] = tip; + assign sr[0] = irq_flag; + +endmodule -- cgit v1.2.3