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

669 lines
24 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 interconnect
*/
module taxi_axi_interconnect_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,
// Number of regions per master interface
parameter M_REGIONS = 1,
// TODO fix parametrization once verilator issue 5890 is fixed
// 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}}}},
// Secure master (fail operations based on awprot/arprot)
// M_COUNT bits
parameter M_SECURE = {M_COUNT{1'b0}}
)
(
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*M_REGIONS-1:0][31:0] M_ADDR_W_INT = M_ADDR_W;
localparam [M_COUNT-1:0][S_COUNT-1:0] M_CONNECT_INT = M_CONNECT;
localparam [M_COUNT-1:0] M_SECURE_INT = M_SECURE;
// default address computation
function [M_COUNT*M_REGIONS-1:0][ADDR_W-1:0] calcBaseAddrs(input [31:0] dummy);
logic [ADDR_W-1:0] base;
integer width;
logic [ADDR_W-1:0] size;
logic [ADDR_W-1:0] mask;
begin
calcBaseAddrs = '0;
base = '0;
for (integer i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
width = M_ADDR_W_INT[i];
mask = {ADDR_W{1'b1}} >> (ADDR_W - width);
size = mask + 1;
if (width > 0) begin
if ((base & mask) != 0) begin
base = base + size - (base & mask); // align
end
calcBaseAddrs[i] = base;
base = base + size; // increment
end
end
end
endfunction
localparam [M_COUNT*M_REGIONS-1:0][ADDR_W-1:0] M_BASE_ADDR_INT = M_BASE_ADDR != 0 ? (M_COUNT*M_REGIONS*ADDR_W)'(M_BASE_ADDR) : calcBaseAddrs(0);
// 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)");
initial begin
if (M_REGIONS < 1 || M_REGIONS > 16) begin
$error("Error: M_REGIONS must be between 1 and 16 (instance %m)");
$finish;
end
for (integer i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
/* verilator lint_off UNSIGNED */
if (M_ADDR_W_INT[i] != 0 && (M_ADDR_W_INT[i] < $clog2(STRB_W) || M_ADDR_W_INT[i] > ADDR_W)) begin
$error("Error: address width out of range (instance %m)");
$finish;
end
/* verilator lint_on UNSIGNED */
end
$display("Addressing configuration for axi_interconnect instance %m");
for (integer i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
if (M_ADDR_W_INT[i] != 0) begin
$display("%2d (%2d): %x / %02d -- %x-%x",
i/M_REGIONS, i%M_REGIONS,
M_BASE_ADDR_INT[i],
M_ADDR_W_INT[i],
M_BASE_ADDR_INT[i] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[i]),
M_BASE_ADDR_INT[i] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[i]))
);
end
end
for (integer i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
if ((M_BASE_ADDR_INT[i] & (2**M_ADDR_W_INT[i]-1)) != 0) begin
$display("Region not aligned:");
$display("%2d (%2d): %x / %2d -- %x-%x",
i/M_REGIONS, i%M_REGIONS,
M_BASE_ADDR_INT[i],
M_ADDR_W_INT[i],
M_BASE_ADDR_INT[i] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[i]),
M_BASE_ADDR_INT[i] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[i]))
);
$error("Error: address range not aligned (instance %m)");
$finish;
end
end
for (integer i = 0; i < M_COUNT*M_REGIONS; i = i + 1) begin
for (integer j = i+1; j < M_COUNT*M_REGIONS; j = j + 1) begin
if (M_ADDR_W_INT[i] != 0 && M_ADDR_W_INT[j] != 0) begin
if (((M_BASE_ADDR_INT[i] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[i])) <= (M_BASE_ADDR_INT[j] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[j]))))
&& ((M_BASE_ADDR_INT[j] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[j])) <= (M_BASE_ADDR_INT[i] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[i]))))) begin
$display("Overlapping regions:");
$display("%2d (%2d): %x / %2d -- %x-%x",
i/M_REGIONS, i%M_REGIONS,
M_BASE_ADDR_INT[i],
M_ADDR_W_INT[i],
M_BASE_ADDR_INT[i] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[i]),
M_BASE_ADDR_INT[i] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[i]))
);
$display("%2d (%2d): %x / %2d -- %x-%x",
j/M_REGIONS, j%M_REGIONS,
M_BASE_ADDR_INT[j],
M_ADDR_W_INT[j],
M_BASE_ADDR_INT[j] & ({ADDR_W{1'b1}} << M_ADDR_W_INT[j]),
M_BASE_ADDR_INT[j] | ({ADDR_W{1'b1}} >> (ADDR_W - M_ADDR_W_INT[j]))
);
$error("Error: address ranges overlap (instance %m)");
$finish;
end
end
end
end
end
localparam logic [2:0]
STATE_IDLE = 3'd0,
STATE_DECODE = 3'd1,
STATE_WRITE = 3'd2,
STATE_WRITE_RESP = 3'd3,
STATE_WRITE_DROP = 3'd4,
STATE_WAIT_IDLE = 3'd5;
logic [2:0] state_reg = STATE_IDLE, state_next;
logic match;
logic [CL_M_COUNT_INT-1:0] m_select_reg = '0, m_select_next;
logic [S_ID_W-1:0] axi_id_reg = '0, axi_id_next;
logic [ADDR_W-1:0] axi_addr_reg = '0, axi_addr_next;
logic axi_addr_valid_reg = 1'b0, axi_addr_valid_next;
logic [7:0] axi_len_reg = 8'd0, axi_len_next;
logic [2:0] axi_size_reg = 3'd0, axi_size_next;
logic [1:0] axi_burst_reg = 2'd0, axi_burst_next;
logic axi_lock_reg = 1'b0, axi_lock_next;
logic [3:0] axi_cache_reg = 4'd0, axi_cache_next;
logic [2:0] axi_prot_reg = 3'b000, axi_prot_next;
logic [3:0] axi_qos_reg = 4'd0, axi_qos_next;
logic [3:0] axi_region_reg = 4'd0, axi_region_next;
logic [AWUSER_W-1:0] axi_awuser_reg = '0, axi_awuser_next;
logic [1:0] axi_bresp_reg = 2'b00, axi_bresp_next;
logic [BUSER_W-1:0] axi_buser_reg = '0, axi_buser_next;
logic [S_COUNT-1:0] s_axi_awready_reg = '0, s_axi_awready_next;
logic [S_COUNT-1:0] s_axi_wready_reg = '0, s_axi_wready_next;
logic [S_COUNT-1:0] s_axi_bvalid_reg = '0, s_axi_bvalid_next;
logic [M_COUNT-1:0] m_axi_awvalid_reg = '0, m_axi_awvalid_next;
logic [M_COUNT-1:0] m_axi_bready_reg = '0, m_axi_bready_next;
// internal datapath
logic [DATA_W-1:0] m_axi_wdata_int;
logic [STRB_W-1:0] m_axi_wstrb_int;
logic m_axi_wlast_int;
logic [WUSER_W-1:0] m_axi_wuser_int;
logic [M_COUNT-1:0] m_axi_wvalid_int;
logic m_axi_wready_int_reg = 1'b0;
wire m_axi_wready_int_early;
// unpack interface array
wire [S_ID_W-1:0] s_axi_awid[S_COUNT];
wire [ADDR_W-1:0] s_axi_addr[S_COUNT];
wire [7:0] s_axi_awlen[S_COUNT];
wire [2:0] s_axi_awsize[S_COUNT];
wire [1:0] s_axi_awburst[S_COUNT];
wire s_axi_awlock[S_COUNT];
wire [3:0] s_axi_awcache[S_COUNT];
wire [2:0] s_axi_awprot[S_COUNT];
wire [3:0] s_axi_awqos[S_COUNT];
wire [AWUSER_W-1:0] s_axi_awuser[S_COUNT];
wire [S_COUNT-1:0] s_axi_awvalid;
wire [DATA_W-1:0] s_axi_wdata[S_COUNT];
wire [STRB_W-1:0] s_axi_wstrb[S_COUNT];
wire s_axi_wlast[S_COUNT];
wire [WUSER_W-1:0] s_axi_wuser[S_COUNT];
wire [S_COUNT-1:0] s_axi_wvalid;
wire [S_COUNT-1:0] s_axi_bready;
wire [M_COUNT-1:0] m_axi_awready;
wire [M_ID_W-1:0] m_axi_bid[M_COUNT];
wire [1:0] m_axi_bresp[M_COUNT];
wire [BUSER_W-1:0] m_axi_buser[M_COUNT];
wire [M_COUNT-1:0] m_axi_bvalid;
for (genvar n = 0; n < S_COUNT; n = n + 1) begin
assign s_axi_awid[n] = s_axi_wr[n].awid;
assign s_axi_addr[n] = s_axi_wr[n].awaddr;
assign s_axi_awlen[n] = s_axi_wr[n].awlen;
assign s_axi_awsize[n] = s_axi_wr[n].awsize;
assign s_axi_awburst[n] = s_axi_wr[n].awburst;
assign s_axi_awlock[n] = s_axi_wr[n].awlock;
assign s_axi_awcache[n] = s_axi_wr[n].awcache;
assign s_axi_awprot[n] = s_axi_wr[n].awprot;
assign s_axi_awqos[n] = s_axi_wr[n].awqos;
assign s_axi_awuser[n] = s_axi_wr[n].awuser;
assign s_axi_awvalid[n] = s_axi_wr[n].awvalid;
assign s_axi_wr[n].awready = s_axi_awready_reg[n];
assign s_axi_wdata[n] = s_axi_wr[n].wdata;
assign s_axi_wstrb[n] = s_axi_wr[n].wstrb;
assign s_axi_wlast[n] = s_axi_wr[n].wlast;
assign s_axi_wuser[n] = s_axi_wr[n].wuser;
assign s_axi_wvalid[n] = s_axi_wr[n].wvalid;
assign s_axi_wr[n].wready = s_axi_wready_reg[n];
assign s_axi_wr[n].bid = axi_id_reg;
assign s_axi_wr[n].bresp = axi_bresp_reg;
assign s_axi_wr[n].buser = BUSER_EN ? axi_buser_reg : '0;
assign s_axi_wr[n].bvalid = s_axi_bvalid_reg[n];
assign s_axi_bready[n] = s_axi_wr[n].bready;
end
for (genvar n = 0; n < M_COUNT; n = n + 1) begin
assign m_axi_wr[n].awid = axi_id_reg;
assign m_axi_wr[n].awaddr = AXI_M_ADDR_W'(axi_addr_reg);
assign m_axi_wr[n].awlen = axi_len_reg;
assign m_axi_wr[n].awsize = axi_size_reg;
assign m_axi_wr[n].awburst = axi_burst_reg;
assign m_axi_wr[n].awlock = axi_lock_reg;
assign m_axi_wr[n].awcache = axi_cache_reg;
assign m_axi_wr[n].awprot = axi_prot_reg;
assign m_axi_wr[n].awqos = axi_qos_reg;
assign m_axi_wr[n].awuser = AWUSER_EN ? axi_awuser_reg : '0;
assign m_axi_wr[n].awvalid = m_axi_awvalid_reg[n];
assign m_axi_awready[n] = m_axi_wr[n].awready;
assign m_axi_bid[n] = m_axi_wr[n].bid;
assign m_axi_bresp[n] = m_axi_wr[n].bresp;
assign m_axi_buser[n] = m_axi_wr[n].buser;
assign m_axi_bvalid[n] = m_axi_wr[n].bvalid;
assign m_axi_wr[n].bready = m_axi_bready_reg[n];
end
// slave side mux
wire [CL_S_COUNT_INT-1:0] s_select;
wire [S_ID_W-1:0] current_s_axi_awid = s_axi_awid[s_select];
wire [ADDR_W-1:0] current_s_axi_addr = s_axi_addr[s_select];
wire [7:0] current_s_axi_awlen = s_axi_awlen[s_select];
wire [2:0] current_s_axi_awsize = s_axi_awsize[s_select];
wire [1:0] current_s_axi_awburst = s_axi_awburst[s_select];
wire current_s_axi_awlock = s_axi_awlock[s_select];
wire [3:0] current_s_axi_awcache = s_axi_awcache[s_select];
wire [2:0] current_s_axi_awprot = s_axi_awprot[s_select];
wire [3:0] current_s_axi_awqos = s_axi_awqos[s_select];
wire [AWUSER_W-1:0] current_s_axi_awuser = s_axi_awuser[s_select];
wire current_s_axi_awvalid = s_axi_awvalid[s_select];
wire [DATA_W-1:0] current_s_axi_wdata = s_axi_wdata[s_select];
wire [STRB_W-1:0] current_s_axi_wstrb = s_axi_wstrb[s_select];
wire current_s_axi_wlast = s_axi_wlast[s_select];
wire [WUSER_W-1:0] current_s_axi_wuser = s_axi_wuser[s_select];
wire current_s_axi_wvalid = s_axi_wvalid[s_select];
wire current_s_axi_bready = s_axi_bready[s_select];
// master side mux
wire current_m_axi_awready = m_axi_awready[m_select_reg];
wire current_m_axi_wready = m_axi_wready[m_select_reg];
wire [M_ID_W-1:0] current_m_axi_bid = m_axi_bid[m_select_reg];
wire [1:0] current_m_axi_bresp = m_axi_bresp[m_select_reg];
wire [BUSER_W-1:0] current_m_axi_buser = m_axi_buser[m_select_reg];
wire current_m_axi_bvalid = m_axi_bvalid[m_select_reg];
// arbiter instance
wire [S_COUNT-1:0] req;
wire [S_COUNT-1:0] ack;
wire [S_COUNT-1:0] grant;
wire grant_valid;
wire [CL_S_COUNT_INT-1:0] grant_index;
assign s_select = 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)
)
arb_inst (
.clk(clk),
.rst(rst),
.req(req),
.ack(ack),
.grant(grant),
.grant_valid(grant_valid),
.grant_index(grant_index)
);
end else begin
logic grant_valid_reg = 1'b0;
always @(posedge clk) begin
if (req) begin
grant_valid_reg <= 1'b1;
end
if (ack || rst) begin
grant_valid_reg <= 1'b0;
end
end
assign grant_valid = grant_valid_reg;
assign grant = '1;
assign grant_index = '0;
end
assign req = s_axi_awvalid;
assign ack = state_reg == STATE_WAIT_IDLE ? '1 : '0;
always_comb begin
state_next = STATE_IDLE;
match = 1'b0;
m_select_next = m_select_reg;
axi_id_next = axi_id_reg;
axi_addr_next = axi_addr_reg;
axi_addr_valid_next = axi_addr_valid_reg;
axi_len_next = axi_len_reg;
axi_size_next = axi_size_reg;
axi_burst_next = axi_burst_reg;
axi_lock_next = axi_lock_reg;
axi_cache_next = axi_cache_reg;
axi_prot_next = axi_prot_reg;
axi_qos_next = axi_qos_reg;
axi_region_next = axi_region_reg;
axi_awuser_next = axi_awuser_reg;
axi_bresp_next = axi_bresp_reg;
axi_buser_next = axi_buser_reg;
s_axi_awready_next = '0;
s_axi_wready_next = '0;
s_axi_bvalid_next = s_axi_bvalid_reg & ~s_axi_bready;
m_axi_awvalid_next = m_axi_awvalid_reg & ~m_axi_awready;
m_axi_bready_next = '0;
m_axi_wdata_int = current_s_axi_wdata;
m_axi_wstrb_int = current_s_axi_wstrb;
m_axi_wlast_int = current_s_axi_wlast;
m_axi_wuser_int = current_s_axi_wuser;
m_axi_wvalid_int = '0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for arbitration
axi_addr_valid_next = 1'b1;
axi_id_next = current_s_axi_awid;
axi_addr_next = current_s_axi_addr;
axi_len_next = current_s_axi_awlen;
axi_size_next = current_s_axi_awsize;
axi_burst_next = current_s_axi_awburst;
axi_lock_next = current_s_axi_awlock;
axi_cache_next = current_s_axi_awcache;
axi_prot_next = current_s_axi_awprot;
axi_qos_next = current_s_axi_awqos;
axi_awuser_next = current_s_axi_awuser;
if (grant_valid) begin
s_axi_awready_next[s_select] = 1'b1;
state_next = STATE_DECODE;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DECODE: begin
// decode state; determine master interface
match = 1'b0;
for (integer i = 0; i < M_COUNT; i = i + 1) begin
for (integer j = 0; j < M_REGIONS; j = j + 1) begin
if (M_ADDR_W_INT[i*M_REGIONS+j] != 0 && (!M_SECURE_INT[i] || !axi_prot_reg[1]) && M_CONNECT_INT[i][s_select] && (axi_addr_reg >> M_ADDR_W_INT[i*M_REGIONS+j]) == (M_BASE_ADDR_INT[i*M_REGIONS+j] >> M_ADDR_W_INT[i*M_REGIONS+j])) begin
m_select_next = CL_M_COUNT_INT'(i);
match = 1'b1;
end
end
end
axi_bresp_next = 2'b11;
if (match) begin
s_axi_wready_next[s_select] = m_axi_wready_int_early;
state_next = STATE_WRITE;
end else begin
// no match; return decode error
s_axi_wready_next[s_select] = 1'b1;
state_next = STATE_WRITE_DROP;
end
end
STATE_WRITE: begin
// write state; store and forward write data
s_axi_wready_next[s_select] = m_axi_wready_int_early;
if (axi_addr_valid_reg) begin
m_axi_awvalid_next[m_select_reg] = 1'b1;
end
axi_addr_valid_next = 1'b0;
m_axi_wdata_int = current_s_axi_wdata;
m_axi_wstrb_int = current_s_axi_wstrb;
m_axi_wlast_int = current_s_axi_wlast;
m_axi_wuser_int = current_s_axi_wuser;
if (s_axi_wready_reg != 0 && current_s_axi_wvalid) begin
m_axi_wvalid_int[m_select_reg] = 1'b1;
if (current_s_axi_wlast) begin
s_axi_wready_next[s_select] = 1'b0;
m_axi_bready_next[m_select_reg] = s_axi_bvalid_reg == 0;
state_next = STATE_WRITE_RESP;
end else begin
state_next = STATE_WRITE;
end
end else begin
state_next = STATE_WRITE;
end
end
STATE_WRITE_RESP: begin
// write response state; store and forward write response
m_axi_bready_next[m_select_reg] = s_axi_bvalid_reg == 0;
if (m_axi_bready_reg != 0 && current_m_axi_bvalid) begin
m_axi_bready_next[m_select_reg] = 1'b0;
axi_bresp_next = current_m_axi_bresp;
s_axi_bvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
state_next = STATE_WRITE_RESP;
end
end
STATE_WRITE_DROP: begin
// write drop state; drop write data
s_axi_wready_next[s_select] = 1'b1;
axi_addr_valid_next = 1'b0;
if (s_axi_wready_reg != 0 && current_s_axi_wvalid && current_s_axi_wlast) begin
s_axi_wready_next[s_select] = 1'b0;
s_axi_bvalid_next[s_select] = 1'b1;
state_next = STATE_WAIT_IDLE;
end else begin
state_next = STATE_WRITE_DROP;
end
end
STATE_WAIT_IDLE: begin
// wait for idle state; wait untl grant valid is deasserted
if (grant_valid == 0 || ack != 0) begin
state_next = STATE_IDLE;
end else begin
state_next = STATE_WAIT_IDLE;
end
end
default: begin
// invalid state
state_next = STATE_IDLE;
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
s_axi_awready_reg <= s_axi_awready_next;
s_axi_wready_reg <= s_axi_wready_next;
s_axi_bvalid_reg <= s_axi_bvalid_next;
m_axi_awvalid_reg <= m_axi_awvalid_next;
m_axi_bready_reg <= m_axi_bready_next;
m_select_reg <= m_select_next;
axi_id_reg <= axi_id_next;
axi_addr_reg <= axi_addr_next;
axi_addr_valid_reg <= axi_addr_valid_next;
axi_len_reg <= axi_len_next;
axi_size_reg <= axi_size_next;
axi_burst_reg <= axi_burst_next;
axi_lock_reg <= axi_lock_next;
axi_cache_reg <= axi_cache_next;
axi_prot_reg <= axi_prot_next;
axi_qos_reg <= axi_qos_next;
axi_region_reg <= axi_region_next;
axi_awuser_reg <= axi_awuser_next;
axi_bresp_reg <= axi_bresp_next;
axi_buser_reg <= axi_buser_next;
if (rst) begin
state_reg <= STATE_IDLE;
s_axi_awready_reg <= '0;
s_axi_wready_reg <= '0;
s_axi_bvalid_reg <= '0;
m_axi_awvalid_reg <= '0;
m_axi_bready_reg <= '0;
end
end
// output datapath logic (W channel)
logic [DATA_W-1:0] m_axi_wdata_reg = '0;
logic [STRB_W-1:0] m_axi_wstrb_reg = '0;
logic m_axi_wlast_reg = 1'b0;
logic [WUSER_W-1:0] m_axi_wuser_reg = 1'b0;
logic [M_COUNT-1:0] m_axi_wvalid_reg = '0, m_axi_wvalid_next;
logic [DATA_W-1:0] temp_m_axi_wdata_reg = '0;
logic [STRB_W-1:0] temp_m_axi_wstrb_reg = '0;
logic temp_m_axi_wlast_reg = 1'b0;
logic [WUSER_W-1:0] temp_m_axi_wuser_reg = 1'b0;
logic [M_COUNT-1:0] temp_m_axi_wvalid_reg = '0, temp_m_axi_wvalid_next;
// datapath control
logic store_axi_w_int_to_output;
logic store_axi_w_int_to_temp;
logic store_axi_w_temp_to_output;
wire [M_COUNT-1:0] m_axi_wready;
for (genvar n = 0; n < M_COUNT; n = n + 1) begin
assign m_axi_wr[n].wdata = m_axi_wdata_reg;
assign m_axi_wr[n].wstrb = m_axi_wstrb_reg;
assign m_axi_wr[n].wlast = m_axi_wlast_reg;
assign m_axi_wr[n].wuser = WUSER_EN ? m_axi_wuser_reg : '0;
assign m_axi_wr[n].wvalid = m_axi_wvalid_reg[n];
assign m_axi_wready[n] = m_axi_wr[n].wready;
end
// enable ready input next cycle if output is ready or the temp reg will not be filled on the next cycle (output reg empty or no input)
assign m_axi_wready_int_early = (m_axi_wready & m_axi_wvalid_reg) != 0 || (temp_m_axi_wvalid_reg == 0 && (m_axi_wvalid_reg == 0 || m_axi_wvalid_int == 0));
always_comb begin
// transfer sink ready state to source
m_axi_wvalid_next = m_axi_wvalid_reg;
temp_m_axi_wvalid_next = temp_m_axi_wvalid_reg;
store_axi_w_int_to_output = 1'b0;
store_axi_w_int_to_temp = 1'b0;
store_axi_w_temp_to_output = 1'b0;
if (m_axi_wready_int_reg) begin
// input is ready
if ((m_axi_wready & m_axi_wvalid_reg) != 0 || m_axi_wvalid_reg == 0) begin
// output is ready or currently not valid, transfer data to output
m_axi_wvalid_next = m_axi_wvalid_int;
store_axi_w_int_to_output = 1'b1;
end else begin
// output is not ready, store input in temp
temp_m_axi_wvalid_next = m_axi_wvalid_int;
store_axi_w_int_to_temp = 1'b1;
end
end else if ((m_axi_wready & m_axi_wvalid_reg) != 0) begin
// input is not ready, but output is ready
m_axi_wvalid_next = temp_m_axi_wvalid_reg;
temp_m_axi_wvalid_next = '0;
store_axi_w_temp_to_output = 1'b1;
end
end
always_ff @(posedge clk) begin
m_axi_wvalid_reg <= m_axi_wvalid_next;
m_axi_wready_int_reg <= m_axi_wready_int_early;
temp_m_axi_wvalid_reg <= temp_m_axi_wvalid_next;
// datapath
if (store_axi_w_int_to_output) begin
m_axi_wdata_reg <= m_axi_wdata_int;
m_axi_wstrb_reg <= m_axi_wstrb_int;
m_axi_wlast_reg <= m_axi_wlast_int;
m_axi_wuser_reg <= m_axi_wuser_int;
end else if (store_axi_w_temp_to_output) begin
m_axi_wdata_reg <= temp_m_axi_wdata_reg;
m_axi_wstrb_reg <= temp_m_axi_wstrb_reg;
m_axi_wlast_reg <= temp_m_axi_wlast_reg;
m_axi_wuser_reg <= temp_m_axi_wuser_reg;
end
if (store_axi_w_int_to_temp) begin
temp_m_axi_wdata_reg <= m_axi_wdata_int;
temp_m_axi_wstrb_reg <= m_axi_wstrb_int;
temp_m_axi_wlast_reg <= m_axi_wlast_int;
temp_m_axi_wuser_reg <= m_axi_wuser_int;
end
if (rst) begin
m_axi_wvalid_reg <= '0;
m_axi_wready_int_reg <= 1'b0;
temp_m_axi_wvalid_reg <= '0;
end
end
endmodule
`resetall