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corundum/rtl/pcie_tlp_demux.v
Alex Forencich 056500dbf4 Avoid zero-width replication
Signed-off-by: Alex Forencich <alex@alexforencich.com>
2022-06-13 00:52:29 -07:00

342 lines
13 KiB
Verilog

/*
Copyright (c) 2021 Alex Forencich
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// Language: Verilog 2001
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* PCIe TLP demultiplexer
*/
module pcie_tlp_demux #
(
// Output count
parameter PORTS = 2,
// TLP data width
parameter TLP_DATA_WIDTH = 256,
// TLP strobe width
parameter TLP_STRB_WIDTH = TLP_DATA_WIDTH/32,
// TLP header width
parameter TLP_HDR_WIDTH = 128,
// Sequence number width
parameter SEQ_NUM_WIDTH = 6,
// TLP segment count
parameter TLP_SEG_COUNT = 1
)
(
input wire clk,
input wire rst,
/*
* TLP input
*/
input wire [TLP_DATA_WIDTH-1:0] in_tlp_data,
input wire [TLP_STRB_WIDTH-1:0] in_tlp_strb,
input wire [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] in_tlp_hdr,
input wire [TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] in_tlp_seq,
input wire [TLP_SEG_COUNT*3-1:0] in_tlp_bar_id,
input wire [TLP_SEG_COUNT*8-1:0] in_tlp_func_num,
input wire [TLP_SEG_COUNT*4-1:0] in_tlp_error,
input wire [TLP_SEG_COUNT-1:0] in_tlp_valid,
input wire [TLP_SEG_COUNT-1:0] in_tlp_sop,
input wire [TLP_SEG_COUNT-1:0] in_tlp_eop,
output wire in_tlp_ready,
/*
* TLP output
*/
output wire [PORTS*TLP_DATA_WIDTH-1:0] out_tlp_data,
output wire [PORTS*TLP_STRB_WIDTH-1:0] out_tlp_strb,
output wire [PORTS*TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] out_tlp_hdr,
output wire [PORTS*TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] out_tlp_seq,
output wire [PORTS*TLP_SEG_COUNT*3-1:0] out_tlp_bar_id,
output wire [PORTS*TLP_SEG_COUNT*8-1:0] out_tlp_func_num,
output wire [PORTS*TLP_SEG_COUNT*4-1:0] out_tlp_error,
output wire [PORTS*TLP_SEG_COUNT-1:0] out_tlp_valid,
output wire [PORTS*TLP_SEG_COUNT-1:0] out_tlp_sop,
output wire [PORTS*TLP_SEG_COUNT-1:0] out_tlp_eop,
input wire [PORTS-1:0] out_tlp_ready,
/*
* Fields
*/
output wire [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] match_tlp_hdr,
output wire [TLP_SEG_COUNT*3-1:0] match_tlp_bar_id,
output wire [TLP_SEG_COUNT*8-1:0] match_tlp_func_num,
/*
* Control
*/
input wire enable,
input wire [TLP_SEG_COUNT-1:0] drop,
input wire [TLP_SEG_COUNT*PORTS-1:0] select
);
parameter CL_PORTS = $clog2(PORTS);
// check configuration
initial begin
if (TLP_SEG_COUNT != 1) begin
$error("Error: TLP segment count must be 1 (instance %m)");
$finish;
end
if (TLP_HDR_WIDTH != 128) begin
$error("Error: TLP segment header width must be 128 (instance %m)");
$finish;
end
if (TLP_STRB_WIDTH*32 != TLP_DATA_WIDTH) begin
$error("Error: PCIe interface requires dword (32-bit) granularity (instance %m)");
$finish;
end
end
reg [CL_PORTS-1:0] select_reg = 0, select_ctl, select_next;
reg drop_reg = 1'b0, drop_ctl, drop_next;
reg frame_reg = 1'b0, frame_ctl, frame_next;
reg in_tlp_ready_reg = 1'b0, in_tlp_ready_next;
reg [TLP_DATA_WIDTH-1:0] temp_in_tlp_data_reg = 0;
reg [TLP_STRB_WIDTH-1:0] temp_in_tlp_strb_reg = 0;
reg [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] temp_in_tlp_hdr_reg = 0;
reg [TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] temp_in_tlp_seq_reg = 0;
reg [TLP_SEG_COUNT*3-1:0] temp_in_tlp_bar_id_reg = 0;
reg [TLP_SEG_COUNT*8-1:0] temp_in_tlp_func_num_reg = 0;
reg [TLP_SEG_COUNT*4-1:0] temp_in_tlp_error_reg = 0;
reg [TLP_SEG_COUNT-1:0] temp_in_tlp_valid_reg = 1'b0;
reg [TLP_SEG_COUNT-1:0] temp_in_tlp_sop_reg = 1'b0;
reg [TLP_SEG_COUNT-1:0] temp_in_tlp_eop_reg = 1'b0;
// internal datapath
reg [TLP_DATA_WIDTH-1:0] out_tlp_data_int;
reg [TLP_STRB_WIDTH-1:0] out_tlp_strb_int;
reg [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] out_tlp_hdr_int;
reg [TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] out_tlp_seq_int;
reg [TLP_SEG_COUNT*3-1:0] out_tlp_bar_id_int;
reg [TLP_SEG_COUNT*8-1:0] out_tlp_func_num_int;
reg [TLP_SEG_COUNT*4-1:0] out_tlp_error_int;
reg [PORTS*TLP_SEG_COUNT-1:0] out_tlp_valid_int;
reg [TLP_SEG_COUNT-1:0] out_tlp_sop_int;
reg [TLP_SEG_COUNT-1:0] out_tlp_eop_int;
reg out_tlp_ready_int_reg = 1'b0;
wire out_tlp_ready_int_early;
assign in_tlp_ready = in_tlp_ready_reg && enable;
assign match_tlp_hdr = in_tlp_hdr;
assign match_tlp_bar_id = in_tlp_bar_id;
assign match_tlp_func_num = in_tlp_func_num;
integer i;
always @* begin
select_next = select_reg;
select_ctl = select_reg;
drop_next = drop_reg;
drop_ctl = drop_reg;
frame_next = frame_reg;
frame_ctl = frame_reg;
in_tlp_ready_next = 1'b0;
if (in_tlp_valid && in_tlp_ready) begin
// end of frame detection
if (in_tlp_eop) begin
frame_next = 1'b0;
drop_next = 1'b0;
end
end
if (!frame_reg && in_tlp_valid && in_tlp_ready) begin
// start of frame, grab select value
select_ctl = 0;
drop_ctl = 1'b1;
frame_ctl = 1'b1;
for (i = PORTS-1; i >= 0; i = i - 1) begin
if (select[i]) begin
select_ctl = i;
drop_ctl = 1'b0;
end
end
drop_ctl = drop_ctl || drop;
if (!(in_tlp_ready && in_tlp_valid && in_tlp_eop)) begin
select_next = select_ctl;
drop_next = drop_ctl;
frame_next = 1'b1;
end
end
in_tlp_ready_next = out_tlp_ready_int_early || drop_ctl;
out_tlp_data_int = in_tlp_data;
out_tlp_strb_int = in_tlp_strb;
out_tlp_hdr_int = in_tlp_hdr;
out_tlp_seq_int = in_tlp_seq;
out_tlp_bar_id_int = in_tlp_bar_id;
out_tlp_func_num_int = in_tlp_func_num;
out_tlp_error_int = in_tlp_error;
out_tlp_valid_int = (in_tlp_valid && in_tlp_ready && !drop_ctl && frame_ctl) << select_ctl;
out_tlp_sop_int = in_tlp_sop;
out_tlp_eop_int = in_tlp_eop;
end
always @(posedge clk) begin
select_reg <= select_next;
drop_reg <= drop_next;
frame_reg <= frame_next;
in_tlp_ready_reg <= in_tlp_ready_next;
if (rst) begin
select_reg <= 2'd0;
drop_reg <= 1'b0;
frame_reg <= 1'b0;
in_tlp_ready_reg <= 1'b0;
end
end
// output datapath logic
reg [TLP_DATA_WIDTH-1:0] out_tlp_data_reg = 0;
reg [TLP_STRB_WIDTH-1:0] out_tlp_strb_reg = 0;
reg [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] out_tlp_hdr_reg = 0;
reg [TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] out_tlp_seq_reg = 0;
reg [TLP_SEG_COUNT*3-1:0] out_tlp_bar_id_reg = 0;
reg [TLP_SEG_COUNT*8-1:0] out_tlp_func_num_reg = 0;
reg [TLP_SEG_COUNT*4-1:0] out_tlp_error_reg = 0;
reg [PORTS*TLP_SEG_COUNT-1:0] out_tlp_valid_reg = 0, out_tlp_valid_next;
reg [TLP_SEG_COUNT-1:0] out_tlp_sop_reg = 0;
reg [TLP_SEG_COUNT-1:0] out_tlp_eop_reg = 0;
reg [TLP_DATA_WIDTH-1:0] temp_out_tlp_data_reg = 0;
reg [TLP_STRB_WIDTH-1:0] temp_out_tlp_strb_reg = 0;
reg [TLP_SEG_COUNT*TLP_HDR_WIDTH-1:0] temp_out_tlp_hdr_reg = 0;
reg [TLP_SEG_COUNT*SEQ_NUM_WIDTH-1:0] temp_out_tlp_seq_reg = 0;
reg [TLP_SEG_COUNT*3-1:0] temp_out_tlp_bar_id_reg = 0;
reg [TLP_SEG_COUNT*8-1:0] temp_out_tlp_func_num_reg = 0;
reg [TLP_SEG_COUNT*4-1:0] temp_out_tlp_error_reg = 0;
reg [PORTS*TLP_SEG_COUNT-1:0] temp_out_tlp_valid_reg = 0, temp_out_tlp_valid_next;
reg [TLP_SEG_COUNT-1:0] temp_out_tlp_sop_reg = 0;
reg [TLP_SEG_COUNT-1:0] temp_out_tlp_eop_reg = 0;
// datapath control
reg store_int_to_output;
reg store_int_to_temp;
reg store_temp_to_output;
assign out_tlp_data = {PORTS{out_tlp_data_reg}};
assign out_tlp_strb = {PORTS{out_tlp_strb_reg}};
assign out_tlp_hdr = {PORTS{out_tlp_hdr_reg}};
assign out_tlp_seq = {PORTS{out_tlp_seq_reg}};
assign out_tlp_bar_id = {PORTS{out_tlp_bar_id_reg}};
assign out_tlp_func_num = {PORTS{out_tlp_func_num_reg}};
assign out_tlp_error = {PORTS{out_tlp_error_reg}};
assign out_tlp_valid = out_tlp_valid_reg;
assign out_tlp_sop = {PORTS{out_tlp_sop_reg}};
assign out_tlp_eop = {PORTS{out_tlp_eop_reg}};
// enable ready input next cycle if output is ready or if both output registers are empty
assign out_tlp_ready_int_early = (out_tlp_ready & out_tlp_valid) || (!temp_out_tlp_valid_reg && !out_tlp_valid_reg);
always @* begin
// transfer sink ready state to source
out_tlp_valid_next = out_tlp_valid_reg;
temp_out_tlp_valid_next = temp_out_tlp_valid_reg;
store_int_to_output = 1'b0;
store_int_to_temp = 1'b0;
store_temp_to_output = 1'b0;
if (out_tlp_ready_int_reg) begin
// input is ready
if ((out_tlp_ready & out_tlp_valid) || !out_tlp_valid) begin
// output is ready or currently not valid, transfer data to output
out_tlp_valid_next = out_tlp_valid_int;
store_int_to_output = 1'b1;
end else begin
// output is not ready, store input in temp
temp_out_tlp_valid_next = out_tlp_valid_int;
store_int_to_temp = 1'b1;
end
end else if (out_tlp_ready & out_tlp_valid) begin
// input is not ready, but output is ready
out_tlp_valid_next = temp_out_tlp_valid_reg;
temp_out_tlp_valid_next = 1'b0;
store_temp_to_output = 1'b1;
end
end
always @(posedge clk) begin
out_tlp_valid_reg <= out_tlp_valid_next;
out_tlp_ready_int_reg <= out_tlp_ready_int_early;
temp_out_tlp_valid_reg <= temp_out_tlp_valid_next;
// datapath
if (store_int_to_output) begin
out_tlp_data_reg <= out_tlp_data_int;
out_tlp_strb_reg <= out_tlp_strb_int;
out_tlp_hdr_reg <= out_tlp_hdr_int;
out_tlp_seq_reg <= out_tlp_seq_int;
out_tlp_bar_id_reg <= out_tlp_bar_id_int;
out_tlp_func_num_reg <= out_tlp_func_num_int;
out_tlp_error_reg <= out_tlp_error_int;
out_tlp_sop_reg <= out_tlp_sop_int;
out_tlp_eop_reg <= out_tlp_eop_int;
end else if (store_temp_to_output) begin
out_tlp_data_reg <= temp_out_tlp_data_reg;
out_tlp_strb_reg <= temp_out_tlp_strb_reg;
out_tlp_hdr_reg <= temp_out_tlp_hdr_reg;
out_tlp_seq_reg <= temp_out_tlp_seq_reg;
out_tlp_bar_id_reg <= temp_out_tlp_bar_id_reg;
out_tlp_func_num_reg <= temp_out_tlp_func_num_reg;
out_tlp_error_reg <= temp_out_tlp_error_reg;
out_tlp_sop_reg <= temp_out_tlp_sop_reg;
out_tlp_eop_reg <= temp_out_tlp_eop_reg;
end
if (store_int_to_temp) begin
temp_out_tlp_data_reg <= out_tlp_data_int;
temp_out_tlp_strb_reg <= out_tlp_strb_int;
temp_out_tlp_hdr_reg <= out_tlp_hdr_int;
temp_out_tlp_seq_reg <= out_tlp_seq_int;
temp_out_tlp_bar_id_reg <= out_tlp_bar_id_int;
temp_out_tlp_func_num_reg <= out_tlp_func_num_int;
temp_out_tlp_error_reg <= out_tlp_error_int;
temp_out_tlp_sop_reg <= out_tlp_sop_int;
temp_out_tlp_eop_reg <= out_tlp_eop_int;
end
if (rst) begin
out_tlp_valid_reg <= {PORTS{1'b0}};
out_tlp_ready_int_reg <= 1'b0;
temp_out_tlp_valid_reg <= 1'b0;
end
end
endmodule
`resetall