diff options
Diffstat (limited to 'fpga/usrp2/sdr_lib/rx_control.v')
| -rw-r--r-- | fpga/usrp2/sdr_lib/rx_control.v | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/fpga/usrp2/sdr_lib/rx_control.v b/fpga/usrp2/sdr_lib/rx_control.v new file mode 100644 index 000000000..12f411ffe --- /dev/null +++ b/fpga/usrp2/sdr_lib/rx_control.v @@ -0,0 +1,197 @@ +// +// Copyright 2011 Ettus Research LLC +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. +// + + +`define DSP_CORE_RX_BASE 160 + +module rx_control + #(parameter FIFOSIZE = 10) + (input clk, input rst, + input set_stb, input [7:0] set_addr, input [31:0] set_data, + + input [31:0] master_time, + output overrun, + + // To FIFO interface of Buffer Pool + output [31:0] wr_dat_o, + output [3:0] wr_flags_o, + input wr_ready_i, + output wr_ready_o, + + // From DSP Core + input [31:0] sample, + output run, + input strobe, + + // FIFO Levels + output [15:0] fifo_occupied, + output fifo_full, + output fifo_empty, + + // Debug + output [31:0] debug_rx + ); + + wire [31:0] new_time, new_command; + wire sc_pre1, clear_overrun; + wire [31:0] rcvtime_pre; + reg [31:0] rcvtime; + wire [8:0] lines_per_frame; + wire [20:0] numlines; + wire send_imm_pre, chain_pre; + reg send_imm, chain; + wire full_ctrl, read_ctrl, empty_ctrl, write_ctrl; + + setting_reg #(.my_addr(`DSP_CORE_RX_BASE+3)) sr_3 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out(new_time),.changed(sc_pre1)); + + setting_reg #(.my_addr(`DSP_CORE_RX_BASE+4)) sr_4 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out(new_command),.changed()); + + setting_reg #(.my_addr(`DSP_CORE_RX_BASE+5)) sr_5 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out(),.changed(clear_overrun)); + + reg sc_pre2; + always @(posedge clk) + sc_pre2 <= sc_pre1; + assign write_ctrl = sc_pre1 & ~sc_pre2; + + shortfifo #(.WIDTH(64)) commandfifo + (.clk(clk),.rst(rst),.clear(clear_overrun), + .datain({new_command,new_time}), .write(write_ctrl), .full(full_ctrl), + .dataout({send_imm_pre,chain_pre,numlines,lines_per_frame,rcvtime_pre}), + .read(read_ctrl), .empty(empty_ctrl) ); + + // Buffer interface to internal FIFO + wire have_space, write; + wire [35:0] fifo_line; + + // Internal FIFO, size 9 is 2K, size 10 is 4K + fifo_cascade #(.WIDTH(36),.SIZE(FIFOSIZE)) rxfifo + (.clk(clk),.reset(rst),.clear(clear_overrun), + .datain(fifo_line), .src_rdy_i(write), .dst_rdy_o(have_space), + .dataout({wr_flags_o,wr_dat_o}), .src_rdy_o(wr_ready_o), .dst_rdy_i(wr_ready_i), + .space(),.occupied(fifo_occupied) ); + assign fifo_full = ~have_space; + assign fifo_empty = ~wr_ready_o; + + // Internal FIFO to DSP interface + reg [22:0] lines_left; + reg [8:0] lines_left_frame; + localparam IBS_IDLE = 0; + localparam IBS_WAITING = 1; + localparam IBS_FIRSTLINE = 2; + localparam IBS_RUNNING = 3; + localparam IBS_OVERRUN = 4; + + reg [2:0] ibs_state; + + wire [32:0] delta_time = {1'b0,rcvtime}-{1'b0,master_time}; + wire too_late = (delta_time[32:31] == 2'b11) & ~send_imm; + wire go_now = send_imm | ( master_time == rcvtime ); + + always @(posedge clk) + if(rst) + begin + ibs_state <= IBS_IDLE; + lines_left <= 0; + lines_left_frame <= 0; + rcvtime <= 0; + send_imm <= 0; + chain <= 0; + end + else + if(clear_overrun) + begin + ibs_state <= IBS_IDLE; + lines_left <= 0; + lines_left_frame <= 0; + rcvtime <= 0; + send_imm <= 0; + chain <= 0; + end + else + case(ibs_state) + IBS_IDLE : + if(~empty_ctrl) + begin + lines_left <= numlines; + lines_left_frame <= lines_per_frame; + rcvtime <= rcvtime_pre; + ibs_state <= IBS_WAITING; + send_imm <= send_imm_pre; + chain <= chain_pre; + end + IBS_WAITING : + if(go_now) + ibs_state <= IBS_FIRSTLINE; + else if(too_late) + ibs_state <= IBS_OVERRUN; + IBS_FIRSTLINE : + if(~have_space | strobe) + ibs_state <= IBS_OVERRUN; + else + ibs_state <= IBS_RUNNING; + IBS_RUNNING : + if(strobe) + if(~have_space) + ibs_state <= IBS_OVERRUN; + else + begin + lines_left <= lines_left - 1; + if(lines_left == 1) + if(~chain) + ibs_state <= IBS_IDLE; + else if(empty_ctrl) + ibs_state <= IBS_OVERRUN; + else + begin + lines_left <= numlines; + lines_left_frame <= lines_per_frame; + rcvtime <= rcvtime_pre; + ibs_state <= IBS_FIRSTLINE; + send_imm <= send_imm_pre; + chain <= chain_pre; + end + else if(lines_left_frame == 1) + begin + lines_left_frame <= lines_per_frame; + ibs_state <= IBS_FIRSTLINE; + end + else + lines_left_frame <= lines_left_frame - 1; + end // else: !if(~have_space) + endcase // case(ibs_state) + + assign fifo_line = (ibs_state == IBS_FIRSTLINE) ? {2'b0,1'b0,1'b1,master_time} : + {2'b0,((lines_left==1)|(lines_left_frame==1)),1'b0,sample}; + + assign write = ((ibs_state == IBS_FIRSTLINE) | strobe) & have_space; // & (ibs_state == IBS_RUNNING) should strobe only when running + assign overrun = (ibs_state == IBS_OVERRUN); + assign run = (ibs_state == IBS_RUNNING) | (ibs_state == IBS_FIRSTLINE); + assign read_ctrl = ( (ibs_state == IBS_IDLE) | + ((ibs_state == IBS_RUNNING) & strobe & have_space & (lines_left==1) & chain) ) + & ~empty_ctrl; + + assign debug_rx = { 8'd0, + 1'd0, send_imm, chain, wr_ready_i,wr_ready_o, 2'b0, run, + write,have_space,wr_flags_o[1:0],write_ctrl,full_ctrl,read_ctrl,empty_ctrl, + sc_pre1, clear_overrun, go_now, too_late, overrun, ibs_state[2:0] }; +endmodule // rx_control |