Files
taxi-bsl/src/axi/rtl/taxi_axi_crossbar_wr.sv
2025-11-12 22:01:45 -08:00

608 lines
19 KiB
Systemverilog

// SPDX-License-Identifier: CERN-OHL-S-2.0
/*
Copyright (c) 2018-2025 FPGA Ninja, LLC
Authors:
- Alex Forencich
*/
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* AXI4 crossbar (write)
*/
module taxi_axi_crossbar_wr #
(
// Number of AXI inputs (slave interfaces)
parameter S_COUNT = 4,
// Number of AXI outputs (master interfaces)
parameter M_COUNT = 4,
// Address width in bits for address decoding
parameter ADDR_W = 32,
// TODO fix parametrization once verilator issue 5890 is fixed
// Number of concurrent unique IDs for each slave interface
// S_COUNT concatenated fields of 32 bits
parameter S_THREADS = {S_COUNT{32'd2}},
// Number of concurrent operations for each slave interface
// S_COUNT concatenated fields of 32 bits
parameter S_ACCEPT = {S_COUNT{32'd16}},
// Number of regions per master interface
parameter M_REGIONS = 1,
// Master interface base addresses
// M_COUNT concatenated fields of M_REGIONS concatenated fields of ADDR_W bits
// set to zero for default addressing based on M_ADDR_W
parameter M_BASE_ADDR = '0,
// Master interface address widths
// M_COUNT concatenated fields of M_REGIONS concatenated fields of 32 bits
parameter M_ADDR_W = {M_COUNT{{M_REGIONS{32'd24}}}},
// Write connections between interfaces
// M_COUNT concatenated fields of S_COUNT bits
parameter M_CONNECT = {M_COUNT{{S_COUNT{1'b1}}}},
// Number of concurrent operations for each master interface
// M_COUNT concatenated fields of 32 bits
parameter M_ISSUE = {M_COUNT{32'd4}},
// Secure master (fail operations based on awprot/arprot)
// M_COUNT bits
parameter M_SECURE = {M_COUNT{1'b0}},
// Slave interface AW channel register type (input)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter S_AW_REG_TYPE = {S_COUNT{2'd0}},
// Slave interface W channel register type (input)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter S_W_REG_TYPE = {S_COUNT{2'd0}},
// Slave interface B channel register type (output)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter S_B_REG_TYPE = {S_COUNT{2'd1}},
// Master interface AW channel register type (output)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter M_AW_REG_TYPE = {M_COUNT{2'd1}},
// Master interface W channel register type (output)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter M_W_REG_TYPE = {M_COUNT{2'd2}},
// Master interface B channel register type (input)
// 0 to bypass, 1 for simple buffer, 2 for skid buffer
parameter M_B_REG_TYPE = {M_COUNT{2'd0}}
)
(
input wire logic clk,
input wire logic rst,
/*
* AXI4 slave interfaces
*/
taxi_axi_if.wr_slv s_axi_wr[S_COUNT],
/*
* AXI4 master interfaces
*/
taxi_axi_if.wr_mst m_axi_wr[M_COUNT]
);
// extract parameters
localparam DATA_W = s_axi_wr[0].DATA_W;
localparam S_ADDR_W = s_axi_wr[0].ADDR_W;
localparam STRB_W = s_axi_wr[0].STRB_W;
localparam S_ID_W = s_axi_wr[0].ID_W;
localparam M_ID_W = m_axi_wr[0].ID_W;
localparam logic AWUSER_EN = s_axi_wr[0].AWUSER_EN && m_axi_wr[0].AWUSER_EN;
localparam AWUSER_W = s_axi_wr[0].AWUSER_W;
localparam logic WUSER_EN = s_axi_wr[0].WUSER_EN && m_axi_wr[0].WUSER_EN;
localparam WUSER_W = s_axi_wr[0].WUSER_W;
localparam logic BUSER_EN = s_axi_wr[0].BUSER_EN && m_axi_wr[0].BUSER_EN;
localparam BUSER_W = s_axi_wr[0].BUSER_W;
localparam AXI_M_ADDR_W = m_axi_wr[0].ADDR_W;
localparam CL_S_COUNT = $clog2(S_COUNT);
localparam CL_M_COUNT = $clog2(M_COUNT);
localparam CL_S_COUNT_INT = CL_S_COUNT > 0 ? CL_S_COUNT : 1;
localparam CL_M_COUNT_INT = CL_M_COUNT > 0 ? CL_M_COUNT : 1;
localparam M_COUNT_P1 = M_COUNT+1;
localparam CL_M_COUNT_P1 = $clog2(M_COUNT_P1);
localparam [S_COUNT-1:0][31:0] S_THREADS_INT = S_THREADS;
localparam [S_COUNT-1:0][31:0] S_ACCEPT_INT = S_ACCEPT;
localparam [M_COUNT-1:0][31:0] M_ISSUE_INT = M_ISSUE;
// check configuration
if (s_axi_wr[0].ADDR_W != ADDR_W)
$fatal(0, "Error: Interface ADDR_W parameter mismatch (instance %m)");
if (m_axi_wr[0].DATA_W != DATA_W)
$fatal(0, "Error: Interface DATA_W parameter mismatch (instance %m)");
if (m_axi_wr[0].STRB_W != STRB_W)
$fatal(0, "Error: Interface STRB_W parameter mismatch (instance %m)");
if (M_ID_W < S_ID_W+$clog2(S_COUNT))
$fatal(0, "Error: M_ID_W must be at least $clog2(S_COUNT) larger than S_ID_W (instance %m)");
wire [S_ID_W-1:0] int_s_axi_awid[S_COUNT];
wire [ADDR_W-1:0] int_s_axi_awaddr[S_COUNT];
wire [7:0] int_s_axi_awlen[S_COUNT];
wire [2:0] int_s_axi_awsize[S_COUNT];
wire [1:0] int_s_axi_awburst[S_COUNT];
wire int_s_axi_awlock[S_COUNT];
wire [3:0] int_s_axi_awcache[S_COUNT];
wire [2:0] int_s_axi_awprot[S_COUNT];
wire [3:0] int_s_axi_awqos[S_COUNT];
wire [3:0] int_s_axi_awregion[S_COUNT];
wire [AWUSER_W-1:0] int_s_axi_awuser[S_COUNT];
logic [M_COUNT-1:0] int_axi_awvalid[S_COUNT];
logic [S_COUNT-1:0] int_axi_awready[M_COUNT];
wire [DATA_W-1:0] int_s_axi_wdata[S_COUNT];
wire [STRB_W-1:0] int_s_axi_wstrb[S_COUNT];
wire int_s_axi_wlast[S_COUNT];
wire [WUSER_W-1:0] int_s_axi_wuser[S_COUNT];
logic [M_COUNT-1:0] int_axi_wvalid[S_COUNT];
logic [S_COUNT-1:0] int_axi_wready[M_COUNT];
wire [M_ID_W-1:0] int_m_axi_bid[M_COUNT];
wire [1:0] int_m_axi_bresp[M_COUNT];
wire [BUSER_W-1:0] int_m_axi_buser[M_COUNT];
logic [S_COUNT-1:0] int_axi_bvalid[M_COUNT];
logic [M_COUNT-1:0] int_axi_bready[S_COUNT];
for (genvar m = 0; m < S_COUNT; m = m + 1) begin : s_ifaces
taxi_axi_if #(
.DATA_W(s_axi_wr[0].DATA_W),
.ADDR_W(s_axi_wr[0].ADDR_W),
.STRB_W(s_axi_wr[0].STRB_W),
.ID_W(s_axi_wr[0].ID_W),
.AWUSER_EN(s_axi_wr[0].AWUSER_EN),
.AWUSER_W(s_axi_wr[0].AWUSER_W),
.WUSER_EN(s_axi_wr[0].WUSER_EN),
.WUSER_W(s_axi_wr[0].WUSER_W),
.BUSER_EN(s_axi_wr[0].BUSER_EN),
.BUSER_W(s_axi_wr[0].BUSER_W)
) int_axi();
// S side register
taxi_axi_register_wr #(
.AW_REG_TYPE(S_AW_REG_TYPE[m*2 +: 2]),
.W_REG_TYPE(S_W_REG_TYPE[m*2 +: 2]),
.B_REG_TYPE(S_B_REG_TYPE[m*2 +: 2])
)
reg_inst (
.clk(clk),
.rst(rst),
/*
* AXI4 slave interface
*/
.s_axi_wr(s_axi_wr[m]),
/*
* AXI4 master interface
*/
.m_axi_wr(int_axi)
);
// address decode and admission control
wire [CL_M_COUNT_INT-1:0] a_select;
wire m_axi_avalid;
wire m_axi_aready;
wire [CL_M_COUNT_INT-1:0] m_wc_select;
wire m_wc_decerr;
wire m_wc_valid;
wire m_wc_ready;
wire m_rc_decerr;
wire m_rc_valid;
wire m_rc_ready;
wire [S_ID_W-1:0] s_cpl_id;
wire s_cpl_valid;
taxi_axi_crossbar_addr #(
.S(m),
.S_COUNT(S_COUNT),
.M_COUNT(M_COUNT),
.SEL_W(CL_M_COUNT_INT),
.ADDR_W(ADDR_W),
.ID_W(S_ID_W),
.S_THREADS(S_THREADS_INT[m]),
.S_ACCEPT(S_ACCEPT_INT[m]),
.M_REGIONS(M_REGIONS),
.M_BASE_ADDR(M_BASE_ADDR),
.M_ADDR_W(M_ADDR_W),
.M_CONNECT(M_CONNECT),
.M_SECURE(M_SECURE),
.WC_OUTPUT(1)
)
addr_inst (
.clk(clk),
.rst(rst),
/*
* Address input
*/
.s_axi_aid(int_axi.awid),
.s_axi_aaddr(int_axi.awaddr),
.s_axi_aprot(int_axi.awprot),
.s_axi_aqos(int_axi.awqos),
.s_axi_avalid(int_axi.awvalid),
.s_axi_aready(int_axi.awready),
/*
* Address output
*/
.m_axi_aregion(int_s_axi_awregion[m]),
.m_select(a_select),
.m_axi_avalid(m_axi_avalid),
.m_axi_aready(m_axi_aready),
/*
* Write command output
*/
.m_wc_select(m_wc_select),
.m_wc_decerr(m_wc_decerr),
.m_wc_valid(m_wc_valid),
.m_wc_ready(m_wc_ready),
/*
* Response command output
*/
.m_rc_decerr(m_rc_decerr),
.m_rc_valid(m_rc_valid),
.m_rc_ready(m_rc_ready),
/*
* Completion input
*/
.s_cpl_id(s_cpl_id),
.s_cpl_valid(s_cpl_valid)
);
assign int_s_axi_awid[m] = int_axi.awid;
assign int_s_axi_awaddr[m] = int_axi.awaddr;
assign int_s_axi_awlen[m] = int_axi.awlen;
assign int_s_axi_awsize[m] = int_axi.awsize;
assign int_s_axi_awburst[m] = int_axi.awburst;
assign int_s_axi_awlock[m] = int_axi.awlock;
assign int_s_axi_awcache[m] = int_axi.awcache;
assign int_s_axi_awprot[m] = int_axi.awprot;
assign int_s_axi_awqos[m] = int_axi.awqos;
assign int_s_axi_awuser[m] = int_axi.awuser;
always_comb begin
int_axi_awvalid[m] = '0;
int_axi_awvalid[m][a_select] = m_axi_avalid;
end
assign m_axi_aready = int_axi_awready[a_select][m];
// write command handling
logic [CL_M_COUNT_INT-1:0] w_select_reg = '0, w_select_next;
logic w_drop_reg = 1'b0, w_drop_next;
logic w_select_valid_reg = 1'b0, w_select_valid_next;
assign m_wc_ready = !w_select_valid_reg;
always_comb begin
w_select_next = w_select_reg;
w_drop_next = w_drop_reg && !(int_axi.wvalid && int_axi.wready && int_axi.wlast);
w_select_valid_next = w_select_valid_reg && !(int_axi.wvalid && int_axi.wready && int_axi.wlast);
if (m_wc_valid && !w_select_valid_reg) begin
w_select_next = m_wc_select;
w_drop_next = m_wc_decerr;
w_select_valid_next = m_wc_valid;
end
end
always_ff @(posedge clk) begin
w_select_valid_reg <= w_select_valid_next;
w_select_reg <= w_select_next;
w_drop_reg <= w_drop_next;
if (rst) begin
w_select_valid_reg <= 1'b0;
end
end
// write data forwarding
assign int_s_axi_wdata[m] = int_axi.wdata;
assign int_s_axi_wstrb[m] = int_axi.wstrb;
assign int_s_axi_wlast[m] = int_axi.wlast;
assign int_s_axi_wuser[m] = int_axi.wuser;
always_comb begin
int_axi_wvalid[m] = '0;
int_axi_wvalid[m][w_select_reg] = int_axi.wvalid && w_select_valid_reg && !w_drop_reg;
end
assign int_axi.wready = int_axi_wready[w_select_reg][m] || w_drop_reg;
// decode error handling
logic [S_ID_W-1:0] decerr_m_axi_bid_reg = '0, decerr_m_axi_bid_next;
logic decerr_m_axi_bvalid_reg = 1'b0, decerr_m_axi_bvalid_next;
wire decerr_m_axi_bready;
assign m_rc_ready = !decerr_m_axi_bvalid_reg;
always_comb begin
decerr_m_axi_bid_next = decerr_m_axi_bid_reg;
decerr_m_axi_bvalid_next = decerr_m_axi_bvalid_reg;
if (decerr_m_axi_bvalid_reg) begin
if (decerr_m_axi_bready) begin
decerr_m_axi_bvalid_next = 1'b0;
end
end else if (m_rc_valid && m_rc_ready) begin
decerr_m_axi_bid_next = int_s_axi_awid[m];
decerr_m_axi_bvalid_next = 1'b1;
end
end
always_ff @(posedge clk) begin
if (rst) begin
decerr_m_axi_bvalid_reg <= 1'b0;
end else begin
decerr_m_axi_bvalid_reg <= decerr_m_axi_bvalid_next;
end
decerr_m_axi_bid_reg <= decerr_m_axi_bid_next;
end
// write response arbitration
wire [M_COUNT_P1-1:0] b_req;
wire [M_COUNT_P1-1:0] b_ack;
wire [M_COUNT_P1-1:0] b_grant;
wire b_grant_valid;
wire [CL_M_COUNT_P1-1:0] b_grant_index;
taxi_arbiter #(
.PORTS(M_COUNT_P1),
.ARB_ROUND_ROBIN(1),
.ARB_BLOCK(1),
.ARB_BLOCK_ACK(1),
.LSB_HIGH_PRIO(1)
)
b_arb_inst (
.clk(clk),
.rst(rst),
.req(b_req),
.ack(b_ack),
.grant(b_grant),
.grant_valid(b_grant_valid),
.grant_index(b_grant_index)
);
// write response mux
always_comb begin
if (b_grant_index == CL_M_COUNT_P1'(M_COUNT_P1-1)) begin
int_axi.bid = decerr_m_axi_bid_reg;
int_axi.bresp = 2'b11;
int_axi.buser = '0;
int_axi.bvalid = decerr_m_axi_bvalid_reg & b_grant_valid;
end else begin
int_axi.bid = S_ID_W'(int_m_axi_bid[b_grant_index[CL_M_COUNT_INT-1:0]]);
int_axi.bresp = int_m_axi_bresp[b_grant_index[CL_M_COUNT_INT-1:0]];
int_axi.buser = int_m_axi_buser[b_grant_index[CL_M_COUNT_INT-1:0]];
int_axi.bvalid = int_axi_bvalid[b_grant_index[CL_M_COUNT_INT-1:0]][m] & b_grant_valid;
end
end
always_comb begin
int_axi_bready[m] = '0;
int_axi_bready[m][b_grant_index[CL_M_COUNT_INT-1:0]] = b_grant_valid && int_axi.bready;
end
assign decerr_m_axi_bready = (b_grant_valid && int_axi.bready) && (b_grant_index == CL_M_COUNT_P1'(M_COUNT_P1-1));
for (genvar n = 0; n < M_COUNT; n = n + 1) begin
assign b_req[n] = int_axi_bvalid[n][m] && !b_grant[n];
assign b_ack[n] = b_grant[n] && int_axi_bvalid[n][m] && int_axi.bready;
end
assign b_req[M_COUNT_P1-1] = decerr_m_axi_bvalid_reg && !b_grant[M_COUNT_P1-1];
assign b_ack[M_COUNT_P1-1] = b_grant[M_COUNT_P1-1] && decerr_m_axi_bvalid_reg && int_axi.bready;
assign s_cpl_id = int_axi.bid;
assign s_cpl_valid = int_axi.bvalid && int_axi.bready;
end // s_ifaces
for (genvar n = 0; n < M_COUNT; n = n + 1) begin : m_ifaces
taxi_axi_if #(
.DATA_W(m_axi_wr[0].DATA_W),
.ADDR_W(m_axi_wr[0].ADDR_W),
.STRB_W(m_axi_wr[0].STRB_W),
.ID_W(m_axi_wr[0].ID_W),
.AWUSER_EN(m_axi_wr[0].AWUSER_EN),
.AWUSER_W(m_axi_wr[0].AWUSER_W),
.WUSER_EN(m_axi_wr[0].WUSER_EN),
.WUSER_W(m_axi_wr[0].WUSER_W),
.BUSER_EN(m_axi_wr[0].BUSER_EN),
.BUSER_W(m_axi_wr[0].BUSER_W)
) int_axi();
// in-flight transaction count
wire trans_start;
wire trans_complete;
localparam TR_CNT_W = $clog2(M_ISSUE_INT[n]+1);
logic [TR_CNT_W-1:0] trans_count_reg = '0;
wire trans_limit = trans_count_reg >= TR_CNT_W'(M_ISSUE_INT[n]) && !trans_complete;
always_ff @(posedge clk) begin
if (trans_start && !trans_complete) begin
trans_count_reg <= trans_count_reg + 1;
end else if (!trans_start && trans_complete) begin
trans_count_reg <= trans_count_reg - 1;
end
if (rst) begin
trans_count_reg <= 0;
end
end
// address arbitration
logic [CL_S_COUNT_INT-1:0] w_select_reg = '0, w_select_next;
logic w_select_valid_reg = 1'b0, w_select_valid_next;
logic w_select_new_reg = 1'b0, w_select_new_next;
wire [S_COUNT-1:0] a_req;
wire [S_COUNT-1:0] a_ack;
wire [S_COUNT-1:0] a_grant;
wire a_grant_valid;
wire [CL_S_COUNT_INT-1:0] a_grant_index;
if (S_COUNT > 1) begin : arb
taxi_arbiter #(
.PORTS(S_COUNT),
.ARB_ROUND_ROBIN(1),
.ARB_BLOCK(1),
.ARB_BLOCK_ACK(1),
.LSB_HIGH_PRIO(1)
)
a_arb_inst (
.clk(clk),
.rst(rst),
.req(a_req),
.ack(a_ack),
.grant(a_grant),
.grant_valid(a_grant_valid),
.grant_index(a_grant_index)
);
end else begin
logic grant_valid_reg = 1'b0;
always @(posedge clk) begin
if (a_req) begin
grant_valid_reg <= 1'b1;
end
if (a_ack || rst) begin
grant_valid_reg <= 1'b0;
end
end
assign a_grant_valid = grant_valid_reg;
assign a_grant = grant_valid_reg;
assign a_grant_index = '0;
end
// address mux
if (S_COUNT > 1) begin
assign int_axi.awid = {a_grant_index, int_s_axi_awid[a_grant_index]};
end else begin
assign int_axi.awid = int_s_axi_awid[a_grant_index];
end
assign int_axi.awaddr = AXI_M_ADDR_W'(int_s_axi_awaddr[a_grant_index]);
assign int_axi.awlen = int_s_axi_awlen[a_grant_index];
assign int_axi.awsize = int_s_axi_awsize[a_grant_index];
assign int_axi.awburst = int_s_axi_awburst[a_grant_index];
assign int_axi.awlock = int_s_axi_awlock[a_grant_index];
assign int_axi.awcache = int_s_axi_awcache[a_grant_index];
assign int_axi.awprot = int_s_axi_awprot[a_grant_index];
assign int_axi.awqos = int_s_axi_awqos[a_grant_index];
assign int_axi.awregion = int_s_axi_awregion[a_grant_index];
assign int_axi.awuser = int_s_axi_awuser[a_grant_index];
assign int_axi.awvalid = int_axi_awvalid[a_grant_index][n] && a_grant_valid;
always_comb begin
int_axi_awready[n] = '0;
int_axi_awready[n][a_grant_index] = a_grant_valid && int_axi.awready;
end
for (genvar m = 0; m < S_COUNT; m = m + 1) begin
assign a_req[m] = int_axi_awvalid[m][n] && !a_grant_valid && !trans_limit && !w_select_valid_next;
assign a_ack[m] = a_grant[m] && int_axi_awvalid[m][n] && int_axi.awready;
end
assign trans_start = int_axi.awvalid && int_axi.awready && a_grant_valid;
// write data mux
assign int_axi.wdata = int_s_axi_wdata[w_select_reg];
assign int_axi.wstrb = int_s_axi_wstrb[w_select_reg];
assign int_axi.wlast = int_s_axi_wlast[w_select_reg];
assign int_axi.wuser = int_s_axi_wuser[w_select_reg];
assign int_axi.wvalid = int_axi_wvalid[w_select_reg][n] && w_select_valid_reg;
always_comb begin
int_axi_wready[n] = '0;
int_axi_wready[n][w_select_reg] = w_select_valid_reg && int_axi.wready;
end
// write data routing
always_comb begin
w_select_next = w_select_reg;
w_select_valid_next = w_select_valid_reg && !(int_axi.wvalid && int_axi.wready && int_axi.wlast);
w_select_new_next = w_select_new_reg || a_grant_valid == 0 || a_ack != 0;
if (a_grant_valid && !w_select_valid_reg && w_select_new_reg) begin
w_select_next = a_grant_index;
w_select_valid_next = a_grant_valid;
w_select_new_next = 1'b0;
end
end
always_ff @(posedge clk) begin
w_select_reg <= w_select_next;
w_select_valid_reg <= w_select_valid_next;
w_select_new_reg <= w_select_new_next;
if (rst) begin
w_select_valid_reg <= 1'b0;
w_select_new_reg <= 1'b1;
end
end
// write response forwarding
wire [CL_S_COUNT_INT-1:0] b_select = CL_S_COUNT_INT'(int_axi.bid >> S_ID_W);
assign int_m_axi_bid[n] = int_axi.bid;
assign int_m_axi_bresp[n] = int_axi.bresp;
assign int_m_axi_buser[n] = int_axi.buser;
always_comb begin
int_axi_bvalid[n] = '0;
int_axi_bvalid[n][b_select] = int_axi.bvalid;
end
assign int_axi.bready = int_axi_bready[b_select][n];
assign trans_complete = int_axi.bvalid && int_axi.bready;
// M side register
taxi_axi_register_wr #(
.AW_REG_TYPE(M_AW_REG_TYPE[n*2 +: 2]),
.W_REG_TYPE(M_W_REG_TYPE[n*2 +: 2]),
.B_REG_TYPE(M_B_REG_TYPE[n*2 +: 2])
)
reg_inst (
.clk(clk),
.rst(rst),
/*
* AXI4 slave interface
*/
.s_axi_wr(int_axi),
/*
* AXI4 master interface
*/
.m_axi_wr(m_axi_wr[n])
);
end // m_ifaces
endmodule
`resetall