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axi: Add AXI width converter module and testbench

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Signed-off-by: Alex Forencich <alex@alexforencich.com>
This commit is contained in:
Alex Forencich
2025-08-30 21:10:08 -07:00
parent 5f6487964e
commit 94a821192c
8 changed files with 2241 additions and 0 deletions
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src/axi/rtl/taxi_axi_adapter.f Normal file
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taxi_axi_adapter.sv
taxi_axi_adapter_wr.sv
taxi_axi_adapter_rd.sv
taxi_axi_if.sv

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src/axi/rtl/taxi_axi_adapter.sv Normal file
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// 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 width adapter
*/
module taxi_axi_adapter #
(
// When adapting to a wider bus, re-pack full-width burst instead of passing through narrow burst if possible
parameter logic CONVERT_BURST = 1'b1,
// When adapting to a wider bus, re-pack all bursts instead of passing through narrow burst if possible
parameter logic CONVERT_NARROW_BURST = 1'b0
)
(
input wire logic clk,
input wire logic rst,
/*
* AXI4 slave interface
*/
taxi_axi_if.wr_slv s_axi_wr,
taxi_axi_if.rd_slv s_axi_rd,
/*
* AXI4 master interface
*/
taxi_axi_if.wr_mst m_axi_wr,
taxi_axi_if.rd_mst m_axi_rd
);
taxi_axi_adapter_wr #(
.CONVERT_BURST(CONVERT_BURST),
.CONVERT_NARROW_BURST(CONVERT_NARROW_BURST)
)
axi_adapter_wr_inst (
.clk(clk),
.rst(rst),
/*
* AXI4 slave interface
*/
.s_axi_wr(s_axi_wr),
/*
* AXI4 master interface
*/
.m_axi_wr(m_axi_wr)
);
taxi_axi_adapter_rd #(
.CONVERT_BURST(CONVERT_BURST),
.CONVERT_NARROW_BURST(CONVERT_NARROW_BURST)
)
axi_adapter_rd_inst (
.clk(clk),
.rst(rst),
/*
* AXI4 slave interface
*/
.s_axi_rd(s_axi_rd),
/*
* AXI4 master interface
*/
.m_axi_rd(m_axi_rd)
);
endmodule
`resetall

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src/axi/rtl/taxi_axi_adapter_rd.sv Normal file
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// 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 width adapter
*/
module taxi_axi_adapter_rd #
(
// When adapting to a wider bus, re-pack full-width burst instead of passing through narrow burst if possible
parameter logic CONVERT_BURST = 1'b1,
// When adapting to a wider bus, re-pack all bursts instead of passing through narrow burst if possible
parameter logic CONVERT_NARROW_BURST = 1'b0
)
(
input wire logic clk,
input wire logic rst,
/*
* AXI4 slave interface
*/
taxi_axi_if.rd_slv s_axi_rd,
/*
* AXI4 master interface
*/
taxi_axi_if.rd_mst m_axi_rd
);
// extract parameters
localparam S_DATA_W = s_axi_rd.DATA_W;
localparam ADDR_W = s_axi_rd.ADDR_W;
localparam CL_ADDR_W = $clog2(ADDR_W);
localparam S_STRB_W = s_axi_rd.STRB_W;
localparam ID_W = s_axi_rd.ID_W;
localparam logic ARUSER_EN = s_axi_rd.ARUSER_EN && m_axi_rd.ARUSER_EN;
localparam ARUSER_W = s_axi_rd.ARUSER_W;
localparam logic RUSER_EN = s_axi_rd.RUSER_EN && m_axi_rd.RUSER_EN;
localparam RUSER_W = s_axi_rd.RUSER_W;
localparam M_DATA_W = m_axi_rd.DATA_W;
localparam M_STRB_W = m_axi_rd.STRB_W;
localparam S_ADDR_BIT_OFFSET = $clog2(S_STRB_W);
localparam M_ADDR_BIT_OFFSET = $clog2(M_STRB_W);
localparam S_BYTE_LANES = S_STRB_W;
localparam M_BYTE_LANES = M_STRB_W;
localparam S_BYTE_SIZE = S_DATA_W/S_BYTE_LANES;
localparam M_BYTE_SIZE = M_DATA_W/M_BYTE_LANES;
localparam logic [2:0] S_BURST_SIZE = 3'($clog2(S_STRB_W));
localparam logic [2:0] M_BURST_SIZE = 3'($clog2(M_STRB_W));
// check configuration
if (S_BYTE_SIZE * S_STRB_W != S_DATA_W)
$fatal(0, "Error: AXI slave interface data width not evenly divisible (instance %m)");
if (M_BYTE_SIZE * M_STRB_W != M_DATA_W)
$fatal(0, "Error: AXI master interface data width not evenly divisible (instance %m)");
if (S_BYTE_SIZE != M_BYTE_SIZE)
$fatal(0, "Error: byte size mismatch (instance %m)");
if (2**$clog2(S_BYTE_LANES) != S_BYTE_LANES)
$fatal(0, "Error: AXI slave interface byte lane count must be even power of two (instance %m)");
if (2**$clog2(M_BYTE_LANES) != M_BYTE_LANES)
$fatal(0, "Error: AXI master interface byte lane count must be even power of two (instance %m)");
if (M_BYTE_LANES == S_BYTE_LANES) begin : bypass
// same width; bypass
assign m_axi_rd.arid = s_axi_rd.arid;
assign m_axi_rd.araddr = s_axi_rd.araddr;
assign m_axi_rd.arlen = s_axi_rd.arlen;
assign m_axi_rd.arsize = s_axi_rd.arsize;
assign m_axi_rd.arburst = s_axi_rd.arburst;
assign m_axi_rd.arlock = s_axi_rd.arlock;
assign m_axi_rd.arcache = s_axi_rd.arcache;
assign m_axi_rd.arprot = s_axi_rd.arprot;
assign m_axi_rd.arqos = s_axi_rd.arqos;
assign m_axi_rd.arregion = s_axi_rd.arregion;
assign m_axi_rd.aruser = ARUSER_EN ? s_axi_rd.aruser : '0;
assign m_axi_rd.arvalid = s_axi_rd.arvalid;
assign s_axi_rd.arready = m_axi_rd.arready;
assign s_axi_rd.rid = m_axi_rd.rid;
assign s_axi_rd.rdata = m_axi_rd.rdata;
assign s_axi_rd.rresp = m_axi_rd.rresp;
assign s_axi_rd.rlast = m_axi_rd.rlast;
assign s_axi_rd.ruser = RUSER_EN ? m_axi_rd.ruser : '0;
assign s_axi_rd.rvalid = m_axi_rd.rvalid;
assign m_axi_rd.rready = s_axi_rd.rready;
end else if (M_BYTE_LANES > S_BYTE_LANES) begin : upsize
// output is wider; upsize
// output bus is wider
localparam EXPAND = M_BYTE_LANES > S_BYTE_LANES;
localparam DATA_W = EXPAND ? M_DATA_W : S_DATA_W;
localparam STRB_W = EXPAND ? M_STRB_W : S_STRB_W;
// required number of segments in wider bus
localparam SEG_COUNT = EXPAND ? (M_BYTE_LANES / S_BYTE_LANES) : (S_BYTE_LANES / M_BYTE_LANES);
localparam CL_SEG_COUNT = $clog2(SEG_COUNT);
// data width and keep width per segment
localparam SEG_DATA_W = DATA_W / SEG_COUNT;
localparam SEG_STRB_W = STRB_W / SEG_COUNT;
localparam [1:0]
STATE_IDLE = 2'd0,
STATE_DATA = 2'd1,
STATE_DATA_READ = 2'd2,
STATE_DATA_SPLIT = 2'd3;
logic [1:0] state_reg = STATE_IDLE, state_next;
logic [ID_W-1:0] id_reg = '0, id_next;
logic [ADDR_W-1:0] addr_reg = '0, addr_next;
logic [DATA_W-1:0] data_reg = '0, data_next;
logic [1:0] resp_reg = '0, resp_next;
logic [RUSER_W-1:0] ruser_reg = '0, ruser_next;
logic [7:0] burst_reg = '0, burst_next;
logic [2:0] burst_size_reg = '0, burst_size_next;
logic [7:0] master_burst_reg = '0, master_burst_next;
logic [2:0] master_burst_size_reg = '0, master_burst_size_next;
logic s_axi_arready_reg = 1'b0, s_axi_arready_next;
logic [ID_W-1:0] m_axi_arid_reg = '0, m_axi_arid_next;
logic [ADDR_W-1:0] m_axi_araddr_reg = '0, m_axi_araddr_next;
logic [7:0] m_axi_arlen_reg = '0, m_axi_arlen_next;
logic [2:0] m_axi_arsize_reg = '0, m_axi_arsize_next;
logic [1:0] m_axi_arburst_reg = '0, m_axi_arburst_next;
logic m_axi_arlock_reg = '0, m_axi_arlock_next;
logic [3:0] m_axi_arcache_reg = '0, m_axi_arcache_next;
logic [2:0] m_axi_arprot_reg = '0, m_axi_arprot_next;
logic [3:0] m_axi_arqos_reg = '0, m_axi_arqos_next;
logic [3:0] m_axi_arregion_reg = '0, m_axi_arregion_next;
logic [ARUSER_W-1:0] m_axi_aruser_reg = '0, m_axi_aruser_next;
logic m_axi_arvalid_reg = 1'b0, m_axi_arvalid_next;
logic m_axi_rready_reg = 1'b0, m_axi_rready_next;
// internal datapath
logic [ID_W-1:0] s_axi_rid_int;
logic [S_DATA_W-1:0] s_axi_rdata_int;
logic [1:0] s_axi_rresp_int;
logic s_axi_rlast_int;
logic [RUSER_W-1:0] s_axi_ruser_int;
logic s_axi_rvalid_int;
logic s_axi_rready_int_reg = 1'b0;
wire s_axi_rready_int_early;
assign s_axi_rd.arready = s_axi_arready_reg;
assign m_axi_rd.arid = '0;
assign m_axi_rd.araddr = m_axi_araddr_reg;
assign m_axi_rd.arlen = m_axi_arlen_reg;
assign m_axi_rd.arsize = m_axi_arsize_reg;
assign m_axi_rd.arburst = m_axi_arburst_reg;
assign m_axi_rd.arlock = m_axi_arlock_reg;
assign m_axi_rd.arcache = m_axi_arcache_reg;
assign m_axi_rd.arprot = m_axi_arprot_reg;
assign m_axi_rd.arqos = m_axi_arqos_reg;
assign m_axi_rd.arregion = m_axi_arregion_reg;
assign m_axi_rd.aruser = ARUSER_EN ? m_axi_aruser_reg : '0;
assign m_axi_rd.arvalid = m_axi_arvalid_reg;
assign m_axi_rd.rready = m_axi_rready_reg;
always_comb begin
state_next = STATE_IDLE;
id_next = id_reg;
addr_next = addr_reg;
data_next = data_reg;
resp_next = resp_reg;
ruser_next = ruser_reg;
burst_next = burst_reg;
burst_size_next = burst_size_reg;
master_burst_next = master_burst_reg;
master_burst_size_next = master_burst_size_reg;
s_axi_arready_next = 1'b0;
m_axi_arid_next = m_axi_arid_reg;
m_axi_araddr_next = m_axi_araddr_reg;
m_axi_arlen_next = m_axi_arlen_reg;
m_axi_arsize_next = m_axi_arsize_reg;
m_axi_arburst_next = m_axi_arburst_reg;
m_axi_arlock_next = m_axi_arlock_reg;
m_axi_arcache_next = m_axi_arcache_reg;
m_axi_arprot_next = m_axi_arprot_reg;
m_axi_arqos_next = m_axi_arqos_reg;
m_axi_arregion_next = m_axi_arregion_reg;
m_axi_aruser_next = m_axi_aruser_reg;
m_axi_arvalid_next = m_axi_arvalid_reg && !m_axi_rd.arready;
m_axi_rready_next = 1'b0;
s_axi_rid_int = id_reg;
s_axi_rdata_int = m_axi_rd.rdata[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_DATA_W +: S_DATA_W];
s_axi_rresp_int = m_axi_rd.rresp;
s_axi_rlast_int = m_axi_rd.rlast;
s_axi_ruser_int = m_axi_rd.ruser;
s_axi_rvalid_int = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for new burst
s_axi_arready_next = !m_axi_rd.arvalid;
if (s_axi_rd.arready && s_axi_rd.arvalid) begin
s_axi_arready_next = 1'b0;
id_next = s_axi_rd.arid;
m_axi_arid_next = s_axi_rd.arid;
m_axi_araddr_next = s_axi_rd.araddr;
addr_next = s_axi_rd.araddr;
burst_next = s_axi_rd.arlen;
burst_size_next = s_axi_rd.arsize;
if (CONVERT_BURST && s_axi_rd.arcache[1] && (CONVERT_NARROW_BURST || s_axi_rd.arsize == S_BURST_SIZE)) begin
// split reads
// require CONVERT_BURST and arcache[1] set
master_burst_size_next = M_BURST_SIZE;
if (CONVERT_NARROW_BURST) begin
m_axi_arlen_next = 8'((({8'd0, s_axi_rd.arlen} << s_axi_rd.arsize) + 16'(s_axi_rd.araddr[M_ADDR_BIT_OFFSET-1:0])) >> M_BURST_SIZE);
end else begin
m_axi_arlen_next = (s_axi_rd.arlen + 8'(s_axi_rd.araddr[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET])) >> CL_SEG_COUNT;
end
m_axi_arsize_next = M_BURST_SIZE;
state_next = STATE_DATA_READ;
end else begin
// output narrow burst
master_burst_size_next = s_axi_rd.arsize;
m_axi_arlen_next = s_axi_rd.arlen;
m_axi_arsize_next = s_axi_rd.arsize;
state_next = STATE_DATA;
end
m_axi_arburst_next = s_axi_rd.arburst;
m_axi_arlock_next = s_axi_rd.arlock;
m_axi_arcache_next = s_axi_rd.arcache;
m_axi_arprot_next = s_axi_rd.arprot;
m_axi_arqos_next = s_axi_rd.arqos;
m_axi_arregion_next = s_axi_rd.arregion;
m_axi_aruser_next = s_axi_rd.aruser;
m_axi_arvalid_next = 1'b1;
m_axi_rready_next = s_axi_rready_int_early;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DATA: begin
m_axi_rready_next = s_axi_rready_int_early;
if (m_axi_rd.rready && m_axi_rd.rvalid) begin
s_axi_rid_int = id_reg;
s_axi_rdata_int = m_axi_rd.rdata[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_DATA_W +: S_DATA_W];
s_axi_rresp_int = m_axi_rd.rresp;
s_axi_rlast_int = m_axi_rd.rlast;
s_axi_ruser_int = m_axi_rd.ruser;
s_axi_rvalid_int = 1'b1;
addr_next = addr_reg + (1 << burst_size_reg);
if (m_axi_rd.rlast) begin
m_axi_rready_next = 1'b0;
s_axi_arready_next = !m_axi_rd.arvalid;
state_next = STATE_IDLE;
end else begin
state_next = STATE_DATA;
end
end else begin
state_next = STATE_DATA;
end
end
STATE_DATA_READ: begin
m_axi_rready_next = s_axi_rready_int_early;
if (m_axi_rd.rready && m_axi_rd.rvalid) begin
s_axi_rid_int = id_reg;
data_next = m_axi_rd.rdata;
resp_next = m_axi_rd.rresp;
ruser_next = m_axi_rd.ruser;
s_axi_rdata_int = m_axi_rd.rdata[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_DATA_W +: S_DATA_W];
s_axi_rresp_int = m_axi_rd.rresp;
s_axi_rlast_int = 1'b0;
s_axi_ruser_int = m_axi_rd.ruser;
s_axi_rvalid_int = 1'b1;
burst_next = burst_reg - 1;
addr_next = addr_reg + (1 << burst_size_reg);
if (burst_reg == 0) begin
m_axi_rready_next = 1'b0;
s_axi_arready_next = !m_axi_rd.arvalid;
s_axi_rlast_int = 1'b1;
state_next = STATE_IDLE;
end else if (addr_next[CL_ADDR_W'(master_burst_size_reg)] != addr_reg[CL_ADDR_W'(master_burst_size_reg)]) begin
state_next = STATE_DATA_READ;
end else begin
m_axi_rready_next = 1'b0;
state_next = STATE_DATA_SPLIT;
end
end else begin
state_next = STATE_DATA_READ;
end
end
STATE_DATA_SPLIT: begin
m_axi_rready_next = 1'b0;
if (s_axi_rready_int_reg) begin
s_axi_rid_int = id_reg;
s_axi_rdata_int = data_reg[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_DATA_W +: S_DATA_W];
s_axi_rresp_int = resp_reg;
s_axi_rlast_int = 1'b0;
s_axi_ruser_int = ruser_reg;
s_axi_rvalid_int = 1'b1;
burst_next = burst_reg - 1;
addr_next = addr_reg + (1 << burst_size_reg);
if (burst_reg == 0) begin
s_axi_arready_next = !m_axi_rd.arvalid;
s_axi_rlast_int = 1'b1;
state_next = STATE_IDLE;
end else if (addr_next[CL_ADDR_W'(master_burst_size_reg)] != addr_reg[CL_ADDR_W'(master_burst_size_reg)]) begin
m_axi_rready_next = s_axi_rready_int_early;
state_next = STATE_DATA_READ;
end else begin
state_next = STATE_DATA_SPLIT;
end
end else begin
state_next = STATE_DATA_SPLIT;
end
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
id_reg <= id_next;
addr_reg <= addr_next;
data_reg <= data_next;
resp_reg <= resp_next;
ruser_reg <= ruser_next;
burst_reg <= burst_next;
burst_size_reg <= burst_size_next;
master_burst_reg <= master_burst_next;
master_burst_size_reg <= master_burst_size_next;
s_axi_arready_reg <= s_axi_arready_next;
m_axi_arid_reg <= m_axi_arid_next;
m_axi_araddr_reg <= m_axi_araddr_next;
m_axi_arlen_reg <= m_axi_arlen_next;
m_axi_arsize_reg <= m_axi_arsize_next;
m_axi_arburst_reg <= m_axi_arburst_next;
m_axi_arlock_reg <= m_axi_arlock_next;
m_axi_arcache_reg <= m_axi_arcache_next;
m_axi_arprot_reg <= m_axi_arprot_next;
m_axi_arqos_reg <= m_axi_arqos_next;
m_axi_arregion_reg <= m_axi_arregion_next;
m_axi_aruser_reg <= m_axi_aruser_next;
m_axi_arvalid_reg <= m_axi_arvalid_next;
m_axi_rready_reg <= m_axi_rready_next;
if (rst) begin
state_reg <= STATE_IDLE;
s_axi_arready_reg <= 1'b0;
m_axi_arvalid_reg <= 1'b0;
m_axi_rready_reg <= 1'b0;
end
end
// output datapath logic
logic [ID_W-1:0] s_axi_rid_reg = '0;
logic [S_DATA_W-1:0] s_axi_rdata_reg = '0;
logic [1:0] s_axi_rresp_reg = 2'd0;
logic s_axi_rlast_reg = 1'b0;
logic [RUSER_W-1:0] s_axi_ruser_reg = 1'b0;
logic s_axi_rvalid_reg = 1'b0, s_axi_rvalid_next;
logic [ID_W-1:0] temp_s_axi_rid_reg = '0;
logic [S_DATA_W-1:0] temp_s_axi_rdata_reg = '0;
logic [1:0] temp_s_axi_rresp_reg = 2'd0;
logic temp_s_axi_rlast_reg = 1'b0;
logic [RUSER_W-1:0] temp_s_axi_ruser_reg = 1'b0;
logic temp_s_axi_rvalid_reg = 1'b0, temp_s_axi_rvalid_next;
// datapath control
logic store_axi_r_int_to_output;
logic store_axi_r_int_to_temp;
logic store_axi_r_temp_to_output;
assign s_axi_rd.rid = s_axi_rid_reg;
assign s_axi_rd.rdata = s_axi_rdata_reg;
assign s_axi_rd.rresp = s_axi_rresp_reg;
assign s_axi_rd.rlast = s_axi_rlast_reg;
assign s_axi_rd.ruser = RUSER_EN ? s_axi_ruser_reg : '0;
assign s_axi_rd.rvalid = s_axi_rvalid_reg;
// 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 s_axi_rready_int_early = s_axi_rd.rready | (~temp_s_axi_rvalid_reg & (~s_axi_rvalid_reg | ~s_axi_rvalid_int));
always_comb begin
// transfer sink ready state to source
s_axi_rvalid_next = s_axi_rvalid_reg;
temp_s_axi_rvalid_next = temp_s_axi_rvalid_reg;
store_axi_r_int_to_output = 1'b0;
store_axi_r_int_to_temp = 1'b0;
store_axi_r_temp_to_output = 1'b0;
if (s_axi_rready_int_reg) begin
// input is ready
if (s_axi_rd.rready | ~s_axi_rvalid_reg) begin
// output is ready or currently not valid, transfer data to output
s_axi_rvalid_next = s_axi_rvalid_int;
store_axi_r_int_to_output = 1'b1;
end else begin
// output is not ready, store input in temp
temp_s_axi_rvalid_next = s_axi_rvalid_int;
store_axi_r_int_to_temp = 1'b1;
end
end else if (s_axi_rd.rready) begin
// input is not ready, but output is ready
s_axi_rvalid_next = temp_s_axi_rvalid_reg;
temp_s_axi_rvalid_next = 1'b0;
store_axi_r_temp_to_output = 1'b1;
end
end
always_ff @(posedge clk) begin
if (rst) begin
s_axi_rvalid_reg <= 1'b0;
s_axi_rready_int_reg <= 1'b0;
temp_s_axi_rvalid_reg <= 1'b0;
end else begin
s_axi_rvalid_reg <= s_axi_rvalid_next;
s_axi_rready_int_reg <= s_axi_rready_int_early;
temp_s_axi_rvalid_reg <= temp_s_axi_rvalid_next;
end
// datapath
if (store_axi_r_int_to_output) begin
s_axi_rid_reg <= s_axi_rid_int;
s_axi_rdata_reg <= s_axi_rdata_int;
s_axi_rresp_reg <= s_axi_rresp_int;
s_axi_rlast_reg <= s_axi_rlast_int;
s_axi_ruser_reg <= s_axi_ruser_int;
end else if (store_axi_r_temp_to_output) begin
s_axi_rid_reg <= temp_s_axi_rid_reg;
s_axi_rdata_reg <= temp_s_axi_rdata_reg;
s_axi_rresp_reg <= temp_s_axi_rresp_reg;
s_axi_rlast_reg <= temp_s_axi_rlast_reg;
s_axi_ruser_reg <= temp_s_axi_ruser_reg;
end
if (store_axi_r_int_to_temp) begin
temp_s_axi_rid_reg <= s_axi_rid_int;
temp_s_axi_rdata_reg <= s_axi_rdata_int;
temp_s_axi_rresp_reg <= s_axi_rresp_int;
temp_s_axi_rlast_reg <= s_axi_rlast_int;
temp_s_axi_ruser_reg <= s_axi_ruser_int;
end
end
end else begin : downsize
// output is narrower; downsize
// output bus is wider
localparam EXPAND = M_BYTE_LANES > S_BYTE_LANES;
localparam DATA_W = EXPAND ? M_DATA_W : S_DATA_W;
localparam STRB_W = EXPAND ? M_STRB_W : S_STRB_W;
// required number of segments in wider bus
localparam SEG_COUNT = EXPAND ? (M_BYTE_LANES / S_BYTE_LANES) : (S_BYTE_LANES / M_BYTE_LANES);
// data width and keep width per segment
localparam SEG_DATA_W = DATA_W / SEG_COUNT;
localparam SEG_STRB_W = STRB_W / SEG_COUNT;
localparam [0:0]
STATE_IDLE = 1'd0,
STATE_DATA = 1'd1;
logic [0:0] state_reg = STATE_IDLE, state_next;
logic [ID_W-1:0] id_reg = '0, id_next;
logic [ADDR_W-1:0] addr_reg = '0, addr_next;
logic [DATA_W-1:0] data_reg = '0, data_next;
logic [1:0] resp_reg = '0, resp_next;
logic [RUSER_W-1:0] ruser_reg = '0, ruser_next;
logic [7:0] burst_reg = '0, burst_next;
logic [2:0] burst_size_reg = '0, burst_size_next;
logic [7:0] master_burst_reg = '0, master_burst_next;
logic [2:0] master_burst_size_reg = '0, master_burst_size_next;
logic s_axi_arready_reg = 1'b0, s_axi_arready_next;
logic [ID_W-1:0] m_axi_arid_reg = '0, m_axi_arid_next;
logic [ADDR_W-1:0] m_axi_araddr_reg = '0, m_axi_araddr_next;
logic [7:0] m_axi_arlen_reg = '0, m_axi_arlen_next;
logic [2:0] m_axi_arsize_reg = '0, m_axi_arsize_next;
logic [1:0] m_axi_arburst_reg = '0, m_axi_arburst_next;
logic m_axi_arlock_reg = '0, m_axi_arlock_next;
logic [3:0] m_axi_arcache_reg = '0, m_axi_arcache_next;
logic [2:0] m_axi_arprot_reg = '0, m_axi_arprot_next;
logic [3:0] m_axi_arqos_reg = '0, m_axi_arqos_next;
logic [3:0] m_axi_arregion_reg = '0, m_axi_arregion_next;
logic [ARUSER_W-1:0] m_axi_aruser_reg = '0, m_axi_aruser_next;
logic m_axi_arvalid_reg = 1'b0, m_axi_arvalid_next;
logic m_axi_rready_reg = 1'b0, m_axi_rready_next;
// internal datapath
logic [ID_W-1:0] s_axi_rid_int;
logic [S_DATA_W-1:0] s_axi_rdata_int;
logic [1:0] s_axi_rresp_int;
logic s_axi_rlast_int;
logic [RUSER_W-1:0] s_axi_ruser_int;
logic s_axi_rvalid_int;
logic s_axi_rready_int_reg = 1'b0;
wire s_axi_rready_int_early;
assign s_axi_rd.arready = s_axi_arready_reg;
assign m_axi_rd.arid = '0;
assign m_axi_rd.araddr = m_axi_araddr_reg;
assign m_axi_rd.arlen = m_axi_arlen_reg;
assign m_axi_rd.arsize = m_axi_arsize_reg;
assign m_axi_rd.arburst = m_axi_arburst_reg;
assign m_axi_rd.arlock = m_axi_arlock_reg;
assign m_axi_rd.arcache = m_axi_arcache_reg;
assign m_axi_rd.arprot = m_axi_arprot_reg;
assign m_axi_rd.arqos = m_axi_arqos_reg;
assign m_axi_rd.arregion = m_axi_arregion_reg;
assign m_axi_rd.aruser = ARUSER_EN ? m_axi_aruser_reg : '0;
assign m_axi_rd.arvalid = m_axi_arvalid_reg;
assign m_axi_rd.rready = m_axi_rready_reg;
always_comb begin
state_next = STATE_IDLE;
id_next = id_reg;
addr_next = addr_reg;
data_next = data_reg;
resp_next = resp_reg;
ruser_next = ruser_reg;
burst_next = burst_reg;
burst_size_next = burst_size_reg;
master_burst_next = master_burst_reg;
master_burst_size_next = master_burst_size_reg;
s_axi_arready_next = 1'b0;
m_axi_arid_next = m_axi_arid_reg;
m_axi_araddr_next = m_axi_araddr_reg;
m_axi_arlen_next = m_axi_arlen_reg;
m_axi_arsize_next = m_axi_arsize_reg;
m_axi_arburst_next = m_axi_arburst_reg;
m_axi_arlock_next = m_axi_arlock_reg;
m_axi_arcache_next = m_axi_arcache_reg;
m_axi_arprot_next = m_axi_arprot_reg;
m_axi_arqos_next = m_axi_arqos_reg;
m_axi_arregion_next = m_axi_arregion_reg;
m_axi_aruser_next = m_axi_aruser_reg;
m_axi_arvalid_next = m_axi_arvalid_reg && !m_axi_rd.arready;
m_axi_rready_next = 1'b0;
// master output is narrower; merge reads and possibly split burst
s_axi_rid_int = id_reg;
s_axi_rdata_int = data_reg;
s_axi_rresp_int = resp_reg;
s_axi_rlast_int = 1'b0;
s_axi_ruser_int = m_axi_rd.ruser;
s_axi_rvalid_int = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for new burst
s_axi_arready_next = !m_axi_rd.arvalid;
resp_next = 2'd0;
if (s_axi_rd.arready && s_axi_rd.arvalid) begin
s_axi_arready_next = 1'b0;
id_next = s_axi_rd.arid;
m_axi_arid_next = s_axi_rd.arid;
m_axi_araddr_next = s_axi_rd.araddr;
addr_next = s_axi_rd.araddr;
burst_next = s_axi_rd.arlen;
burst_size_next = s_axi_rd.arsize;
if (s_axi_rd.arsize > M_BURST_SIZE) begin
// need to adjust burst size
if (s_axi_rd.arlen >> (8+M_BURST_SIZE-s_axi_rd.arsize) != 0) begin
// limit burst length to max
master_burst_next = 8'(8'd255 << 3'(s_axi_rd.arsize-M_BURST_SIZE)) | 8'((8'(~s_axi_rd.araddr) & 8'(8'hff >> (8-s_axi_rd.arsize))) >> M_BURST_SIZE);
end else begin
master_burst_next = 8'(s_axi_rd.arlen << 3'(s_axi_rd.arsize-M_BURST_SIZE)) | 8'((8'(~s_axi_rd.araddr) & 8'(8'hff >> (8-s_axi_rd.arsize))) >> M_BURST_SIZE);
end
master_burst_size_next = M_BURST_SIZE;
m_axi_arlen_next = master_burst_next;
m_axi_arsize_next = master_burst_size_next;
end else begin
// pass through narrow (enough) burst
master_burst_next = s_axi_rd.arlen;
master_burst_size_next = s_axi_rd.arsize;
m_axi_arlen_next = s_axi_rd.arlen;
m_axi_arsize_next = s_axi_rd.arsize;
end
m_axi_arburst_next = s_axi_rd.arburst;
m_axi_arlock_next = s_axi_rd.arlock;
m_axi_arcache_next = s_axi_rd.arcache;
m_axi_arprot_next = s_axi_rd.arprot;
m_axi_arqos_next = s_axi_rd.arqos;
m_axi_arregion_next = s_axi_rd.arregion;
m_axi_aruser_next = s_axi_rd.aruser;
m_axi_arvalid_next = 1'b1;
m_axi_rready_next = 1'b0;
state_next = STATE_DATA;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DATA: begin
m_axi_rready_next = s_axi_rready_int_early && !m_axi_rd.arvalid;
if (m_axi_rd.rready && m_axi_rd.rvalid) begin
data_next[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET]*SEG_DATA_W +: SEG_DATA_W] = m_axi_rd.rdata;
if (m_axi_rd.rresp != 0) begin
resp_next = m_axi_rd.rresp;
end
s_axi_rid_int = id_reg;
s_axi_rdata_int = data_next;
s_axi_rresp_int = resp_next;
s_axi_rlast_int = 1'b0;
s_axi_ruser_int = m_axi_rd.ruser;
s_axi_rvalid_int = 1'b0;
master_burst_next = master_burst_reg - 1;
addr_next = (addr_reg + (1 << master_burst_size_reg)) & ({ADDR_W{1'b1}} << master_burst_size_reg);
m_axi_araddr_next = addr_next;
if (addr_next[CL_ADDR_W'(burst_size_reg)] != addr_reg[CL_ADDR_W'(burst_size_reg)]) begin
data_next = '0;
burst_next = burst_reg - 1;
s_axi_rvalid_int = 1'b1;
end
if (master_burst_reg == 0) begin
if (burst_next >> (8+M_BURST_SIZE-burst_size_reg) != 0) begin
// limit burst length to max
master_burst_next = 8'd255;
end else begin
master_burst_next = (burst_next << (burst_size_reg-M_BURST_SIZE)) | (8'hff >> (8-burst_size_reg) >> M_BURST_SIZE);
end
m_axi_arlen_next = master_burst_next;
if (burst_reg == 0) begin
m_axi_rready_next = 1'b0;
s_axi_rlast_int = 1'b1;
s_axi_rvalid_int = 1'b1;
s_axi_arready_next = !m_axi_rd.arvalid;
state_next = STATE_IDLE;
end else begin
// start new burst
m_axi_arvalid_next = 1'b1;
m_axi_rready_next = 1'b0;
state_next = STATE_DATA;
end
end else begin
state_next = STATE_DATA;
end
end else begin
state_next = STATE_DATA;
end
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
id_reg <= id_next;
addr_reg <= addr_next;
data_reg <= data_next;
resp_reg <= resp_next;
ruser_reg <= ruser_next;
burst_reg <= burst_next;
burst_size_reg <= burst_size_next;
master_burst_reg <= master_burst_next;
master_burst_size_reg <= master_burst_size_next;
s_axi_arready_reg <= s_axi_arready_next;
m_axi_arid_reg <= m_axi_arid_next;
m_axi_araddr_reg <= m_axi_araddr_next;
m_axi_arlen_reg <= m_axi_arlen_next;
m_axi_arsize_reg <= m_axi_arsize_next;
m_axi_arburst_reg <= m_axi_arburst_next;
m_axi_arlock_reg <= m_axi_arlock_next;
m_axi_arcache_reg <= m_axi_arcache_next;
m_axi_arprot_reg <= m_axi_arprot_next;
m_axi_arqos_reg <= m_axi_arqos_next;
m_axi_arregion_reg <= m_axi_arregion_next;
m_axi_aruser_reg <= m_axi_aruser_next;
m_axi_arvalid_reg <= m_axi_arvalid_next;
m_axi_rready_reg <= m_axi_rready_next;
if (rst) begin
state_reg <= STATE_IDLE;
s_axi_arready_reg <= 1'b0;
m_axi_arvalid_reg <= 1'b0;
m_axi_rready_reg <= 1'b0;
end
end
// output datapath logic
logic [ID_W-1:0] s_axi_rid_reg = '0;
logic [S_DATA_W-1:0] s_axi_rdata_reg = '0;
logic [1:0] s_axi_rresp_reg = 2'd0;
logic s_axi_rlast_reg = 1'b0;
logic [RUSER_W-1:0] s_axi_ruser_reg = 1'b0;
logic s_axi_rvalid_reg = 1'b0, s_axi_rvalid_next;
logic [ID_W-1:0] temp_s_axi_rid_reg = '0;
logic [S_DATA_W-1:0] temp_s_axi_rdata_reg = '0;
logic [1:0] temp_s_axi_rresp_reg = 2'd0;
logic temp_s_axi_rlast_reg = 1'b0;
logic [RUSER_W-1:0] temp_s_axi_ruser_reg = 1'b0;
logic temp_s_axi_rvalid_reg = 1'b0, temp_s_axi_rvalid_next;
// datapath control
logic store_axi_r_int_to_output;
logic store_axi_r_int_to_temp;
logic store_axi_r_temp_to_output;
assign s_axi_rd.rid = s_axi_rid_reg;
assign s_axi_rd.rdata = s_axi_rdata_reg;
assign s_axi_rd.rresp = s_axi_rresp_reg;
assign s_axi_rd.rlast = s_axi_rlast_reg;
assign s_axi_rd.ruser = RUSER_EN ? s_axi_ruser_reg : '0;
assign s_axi_rd.rvalid = s_axi_rvalid_reg;
// 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 s_axi_rready_int_early = s_axi_rd.rready | (~temp_s_axi_rvalid_reg & (~s_axi_rvalid_reg | ~s_axi_rvalid_int));
always_comb begin
// transfer sink ready state to source
s_axi_rvalid_next = s_axi_rvalid_reg;
temp_s_axi_rvalid_next = temp_s_axi_rvalid_reg;
store_axi_r_int_to_output = 1'b0;
store_axi_r_int_to_temp = 1'b0;
store_axi_r_temp_to_output = 1'b0;
if (s_axi_rready_int_reg) begin
// input is ready
if (s_axi_rd.rready | ~s_axi_rvalid_reg) begin
// output is ready or currently not valid, transfer data to output
s_axi_rvalid_next = s_axi_rvalid_int;
store_axi_r_int_to_output = 1'b1;
end else begin
// output is not ready, store input in temp
temp_s_axi_rvalid_next = s_axi_rvalid_int;
store_axi_r_int_to_temp = 1'b1;
end
end else if (s_axi_rd.rready) begin
// input is not ready, but output is ready
s_axi_rvalid_next = temp_s_axi_rvalid_reg;
temp_s_axi_rvalid_next = 1'b0;
store_axi_r_temp_to_output = 1'b1;
end
end
always_ff @(posedge clk) begin
if (rst) begin
s_axi_rvalid_reg <= 1'b0;
s_axi_rready_int_reg <= 1'b0;
temp_s_axi_rvalid_reg <= 1'b0;
end else begin
s_axi_rvalid_reg <= s_axi_rvalid_next;
s_axi_rready_int_reg <= s_axi_rready_int_early;
temp_s_axi_rvalid_reg <= temp_s_axi_rvalid_next;
end
// datapath
if (store_axi_r_int_to_output) begin
s_axi_rid_reg <= s_axi_rid_int;
s_axi_rdata_reg <= s_axi_rdata_int;
s_axi_rresp_reg <= s_axi_rresp_int;
s_axi_rlast_reg <= s_axi_rlast_int;
s_axi_ruser_reg <= s_axi_ruser_int;
end else if (store_axi_r_temp_to_output) begin
s_axi_rid_reg <= temp_s_axi_rid_reg;
s_axi_rdata_reg <= temp_s_axi_rdata_reg;
s_axi_rresp_reg <= temp_s_axi_rresp_reg;
s_axi_rlast_reg <= temp_s_axi_rlast_reg;
s_axi_ruser_reg <= temp_s_axi_ruser_reg;
end
if (store_axi_r_int_to_temp) begin
temp_s_axi_rid_reg <= s_axi_rid_int;
temp_s_axi_rdata_reg <= s_axi_rdata_int;
temp_s_axi_rresp_reg <= s_axi_rresp_int;
temp_s_axi_rlast_reg <= s_axi_rlast_int;
temp_s_axi_ruser_reg <= s_axi_ruser_int;
end
end
end
endmodule
`resetall

904
src/axi/rtl/taxi_axi_adapter_wr.sv Normal file
View File

@@ -0,0 +1,904 @@
// 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 width adapter
*/
module taxi_axi_adapter_wr #
(
// When adapting to a wider bus, re-pack full-width burst instead of passing through narrow burst if possible
parameter logic CONVERT_BURST = 1'b1,
// When adapting to a wider bus, re-pack all bursts instead of passing through narrow burst if possible
parameter logic CONVERT_NARROW_BURST = 1'b0
)
(
input wire logic clk,
input wire logic rst,
/*
* AXI4 slave interface
*/
taxi_axi_if.wr_slv s_axi_wr,
/*
* AXI4 master interface
*/
taxi_axi_if.wr_mst m_axi_wr
);
// extract parameters
localparam S_DATA_W = s_axi_wr.DATA_W;
localparam ADDR_W = s_axi_wr.ADDR_W;
localparam CL_ADDR_W = $clog2(ADDR_W);
localparam S_STRB_W = s_axi_wr.STRB_W;
localparam ID_W = s_axi_wr.ID_W;
localparam logic AWUSER_EN = s_axi_wr.AWUSER_EN && m_axi_wr.AWUSER_EN;
localparam AWUSER_W = s_axi_wr.AWUSER_W;
localparam logic WUSER_EN = s_axi_wr.WUSER_EN && m_axi_wr.WUSER_EN;
localparam WUSER_W = s_axi_wr.WUSER_W;
localparam logic BUSER_EN = s_axi_wr.BUSER_EN && m_axi_wr.BUSER_EN;
localparam BUSER_W = s_axi_wr.BUSER_W;
localparam M_DATA_W = m_axi_wr.DATA_W;
localparam M_STRB_W = m_axi_wr.STRB_W;
localparam S_ADDR_BIT_OFFSET = $clog2(S_STRB_W);
localparam M_ADDR_BIT_OFFSET = $clog2(M_STRB_W);
localparam S_BYTE_LANES = S_STRB_W;
localparam M_BYTE_LANES = M_STRB_W;
localparam S_BYTE_SIZE = S_DATA_W/S_BYTE_LANES;
localparam M_BYTE_SIZE = M_DATA_W/M_BYTE_LANES;
localparam logic [2:0] S_BURST_SIZE = 3'($clog2(S_STRB_W));
localparam logic [2:0] M_BURST_SIZE = 3'($clog2(M_STRB_W));
// check configuration
if (S_BYTE_SIZE * S_STRB_W != S_DATA_W)
$fatal(0, "Error: AXI slave interface data width not evenly divisible (instance %m)");
if (M_BYTE_SIZE * M_STRB_W != M_DATA_W)
$fatal(0, "Error: AXI master interface data width not evenly divisible (instance %m)");
if (S_BYTE_SIZE != M_BYTE_SIZE)
$fatal(0, "Error: byte size mismatch (instance %m)");
if (2**$clog2(S_BYTE_LANES) != S_BYTE_LANES)
$fatal(0, "Error: AXI slave interface byte lane count must be even power of two (instance %m)");
if (2**$clog2(M_BYTE_LANES) != M_BYTE_LANES)
$fatal(0, "Error: AXI master interface byte lane count must be even power of two (instance %m)");
if (M_BYTE_LANES == S_BYTE_LANES) begin : bypass
// same width; bypass
assign m_axi_wr.awid = s_axi_wr.awid;
assign m_axi_wr.awaddr = s_axi_wr.awaddr;
assign m_axi_wr.awlen = s_axi_wr.awlen;
assign m_axi_wr.awsize = s_axi_wr.awsize;
assign m_axi_wr.awburst = s_axi_wr.awburst;
assign m_axi_wr.awlock = s_axi_wr.awlock;
assign m_axi_wr.awcache = s_axi_wr.awcache;
assign m_axi_wr.awprot = s_axi_wr.awprot;
assign m_axi_wr.awqos = s_axi_wr.awqos;
assign m_axi_wr.awregion = s_axi_wr.awregion;
assign m_axi_wr.awuser = AWUSER_EN ? s_axi_wr.awuser : '0;
assign m_axi_wr.awvalid = s_axi_wr.awvalid;
assign s_axi_wr.awready = m_axi_wr.awready;
assign m_axi_wr.wdata = s_axi_wr.wdata;
assign m_axi_wr.wstrb = s_axi_wr.wstrb;
assign m_axi_wr.wlast = s_axi_wr.wlast;
assign m_axi_wr.wuser = WUSER_EN ? s_axi_wr.wuser : '0;
assign m_axi_wr.wvalid = s_axi_wr.wvalid;
assign s_axi_wr.wready = m_axi_wr.wready;
assign s_axi_wr.bid = m_axi_wr.bid;
assign s_axi_wr.bresp = m_axi_wr.bresp;
assign s_axi_wr.buser = BUSER_EN ? m_axi_wr.buser : '0;
assign s_axi_wr.bvalid = m_axi_wr.bvalid;
assign m_axi_wr.bready = s_axi_wr.bready;
end else if (M_BYTE_LANES > S_BYTE_LANES) begin : upsize
// output is wider; upsize
// output bus is wider
localparam EXPAND = M_BYTE_LANES > S_BYTE_LANES;
localparam DATA_W = EXPAND ? M_DATA_W : S_DATA_W;
localparam STRB_W = EXPAND ? M_STRB_W : S_STRB_W;
// required number of segments in wider bus
localparam SEG_COUNT = EXPAND ? (M_BYTE_LANES / S_BYTE_LANES) : (S_BYTE_LANES / M_BYTE_LANES);
localparam CL_SEG_COUNT = $clog2(SEG_COUNT);
// data width and keep width per segment
localparam SEG_DATA_W = DATA_W / SEG_COUNT;
localparam SEG_STRB_W = STRB_W / SEG_COUNT;
localparam [1:0]
STATE_IDLE = 2'd0,
STATE_DATA = 2'd1,
STATE_DATA_2 = 2'd2,
STATE_RESP = 2'd3;
logic [1:0] state_reg = STATE_IDLE, state_next;
logic [ID_W-1:0] id_reg = '0, id_next;
logic [ADDR_W-1:0] addr_reg = '0, addr_next;
logic [DATA_W-1:0] data_reg = '0, data_next;
logic [STRB_W-1:0] strb_reg = '0, strb_next;
logic [WUSER_W-1:0] wuser_reg = '0, wuser_next;
logic [7:0] burst_reg = '0, burst_next;
logic [2:0] burst_size_reg = '0, burst_size_next;
logic [2:0] master_burst_size_reg = '0, master_burst_size_next;
logic burst_active_reg = 1'b0, burst_active_next;
logic first_transfer_reg = 1'b0, first_transfer_next;
logic s_axi_awready_reg = 1'b0, s_axi_awready_next;
logic s_axi_wready_reg = 1'b0, s_axi_wready_next;
logic [ID_W-1:0] s_axi_bid_reg = '0, s_axi_bid_next;
logic [1:0] s_axi_bresp_reg = '0, s_axi_bresp_next;
logic [BUSER_W-1:0] s_axi_buser_reg = '0, s_axi_buser_next;
logic s_axi_bvalid_reg = 1'b0, s_axi_bvalid_next;
logic [ID_W-1:0] m_axi_awid_reg = '0, m_axi_awid_next;
logic [ADDR_W-1:0] m_axi_awaddr_reg = '0, m_axi_awaddr_next;
logic [7:0] m_axi_awlen_reg = '0, m_axi_awlen_next;
logic [2:0] m_axi_awsize_reg = '0, m_axi_awsize_next;
logic [1:0] m_axi_awburst_reg = '0, m_axi_awburst_next;
logic m_axi_awlock_reg = '0, m_axi_awlock_next;
logic [3:0] m_axi_awcache_reg = '0, m_axi_awcache_next;
logic [2:0] m_axi_awprot_reg = '0, m_axi_awprot_next;
logic [3:0] m_axi_awqos_reg = '0, m_axi_awqos_next;
logic [3:0] m_axi_awregion_reg = '0, m_axi_awregion_next;
logic [AWUSER_W-1:0] m_axi_awuser_reg = '0, m_axi_awuser_next;
logic m_axi_awvalid_reg = 1'b0, m_axi_awvalid_next;
logic m_axi_bready_reg = 1'b0, m_axi_bready_next;
// internal datapath
logic [M_DATA_W-1:0] m_axi_wdata_int;
logic [M_STRB_W-1:0] m_axi_wstrb_int;
logic m_axi_wlast_int;
logic [WUSER_W-1:0] m_axi_wuser_int;
logic m_axi_wvalid_int;
logic m_axi_wready_int_reg = 1'b0;
wire m_axi_wready_int_early;
assign s_axi_wr.awready = s_axi_awready_reg;
assign s_axi_wr.wready = s_axi_wready_reg;
assign s_axi_wr.bid = s_axi_bid_reg;
assign s_axi_wr.bresp = s_axi_bresp_reg;
assign s_axi_wr.buser = BUSER_EN ? s_axi_buser_reg : '0;
assign s_axi_wr.bvalid = s_axi_bvalid_reg;
assign m_axi_wr.awid = '0;
assign m_axi_wr.awaddr = m_axi_awaddr_reg;
assign m_axi_wr.awlen = m_axi_awlen_reg;
assign m_axi_wr.awsize = m_axi_awsize_reg;
assign m_axi_wr.awburst = m_axi_awburst_reg;
assign m_axi_wr.awlock = m_axi_awlock_reg;
assign m_axi_wr.awcache = m_axi_awcache_reg;
assign m_axi_wr.awprot = m_axi_awprot_reg;
assign m_axi_wr.awqos = m_axi_awqos_reg;
assign m_axi_wr.awregion = m_axi_awregion_reg;
assign m_axi_wr.awuser = AWUSER_EN ? m_axi_awuser_reg : '0;
assign m_axi_wr.awvalid = m_axi_awvalid_reg;
assign m_axi_wr.bready = m_axi_bready_reg;
always_comb begin
state_next = STATE_IDLE;
id_next = id_reg;
addr_next = addr_reg;
data_next = data_reg;
strb_next = strb_reg;
wuser_next = wuser_reg;
burst_next = burst_reg;
burst_size_next = burst_size_reg;
master_burst_size_next = master_burst_size_reg;
burst_active_next = burst_active_reg;
first_transfer_next = first_transfer_reg;
s_axi_awready_next = 1'b0;
s_axi_wready_next = 1'b0;
s_axi_bid_next = s_axi_bid_reg;
s_axi_bresp_next = s_axi_bresp_reg;
s_axi_buser_next = s_axi_buser_reg;
s_axi_bvalid_next = s_axi_bvalid_reg && !s_axi_wr.bready;
m_axi_awid_next = m_axi_awid_reg;
m_axi_awaddr_next = m_axi_awaddr_reg;
m_axi_awlen_next = m_axi_awlen_reg;
m_axi_awsize_next = m_axi_awsize_reg;
m_axi_awburst_next = m_axi_awburst_reg;
m_axi_awlock_next = m_axi_awlock_reg;
m_axi_awcache_next = m_axi_awcache_reg;
m_axi_awprot_next = m_axi_awprot_reg;
m_axi_awqos_next = m_axi_awqos_reg;
m_axi_awregion_next = m_axi_awregion_reg;
m_axi_awuser_next = m_axi_awuser_reg;
m_axi_awvalid_next = m_axi_awvalid_reg && !m_axi_wr.awready;
m_axi_bready_next = 1'b0;
m_axi_wdata_int = {(M_BYTE_LANES/S_BYTE_LANES){s_axi_wr.wdata}};
m_axi_wstrb_int = 0;
m_axi_wstrb_int[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_STRB_W +: S_STRB_W] = s_axi_wr.wstrb;
m_axi_wlast_int = s_axi_wr.wlast;
m_axi_wuser_int = s_axi_wr.wuser;
m_axi_wvalid_int = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for new burst
s_axi_awready_next = !m_axi_wr.awvalid;
strb_next = '0;
if (s_axi_wr.awready && s_axi_wr.awvalid) begin
s_axi_awready_next = 1'b0;
id_next = s_axi_wr.awid;
m_axi_awid_next = s_axi_wr.awid;
m_axi_awaddr_next = s_axi_wr.awaddr;
addr_next = s_axi_wr.awaddr;
burst_next = s_axi_wr.awlen;
burst_size_next = s_axi_wr.awsize;
if (CONVERT_BURST && s_axi_wr.awcache[1] && (CONVERT_NARROW_BURST || s_axi_wr.awsize == S_BURST_SIZE)) begin
// merge writes
// require CONVERT_BURST and awcache[1] set
master_burst_size_next = M_BURST_SIZE;
if (CONVERT_NARROW_BURST) begin
m_axi_awlen_next = 8'((({8'd0, s_axi_wr.awlen} << s_axi_wr.awsize) + 16'(s_axi_wr.awaddr[M_ADDR_BIT_OFFSET-1:0])) >> M_BURST_SIZE);
end else begin
m_axi_awlen_next = (s_axi_wr.awlen + 8'(s_axi_wr.awaddr[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET])) >> CL_SEG_COUNT;
end
m_axi_awsize_next = M_BURST_SIZE;
state_next = STATE_DATA_2;
end else begin
// output narrow burst
master_burst_size_next = s_axi_wr.awsize;
m_axi_awlen_next = s_axi_wr.awlen;
m_axi_awsize_next = s_axi_wr.awsize;
state_next = STATE_DATA;
end
m_axi_awburst_next = s_axi_wr.awburst;
m_axi_awlock_next = s_axi_wr.awlock;
m_axi_awcache_next = s_axi_wr.awcache;
m_axi_awprot_next = s_axi_wr.awprot;
m_axi_awqos_next = s_axi_wr.awqos;
m_axi_awregion_next = s_axi_wr.awregion;
m_axi_awuser_next = s_axi_wr.awuser;
m_axi_awvalid_next = 1'b1;
s_axi_wready_next = m_axi_wready_int_early;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DATA: begin
// data state; transfer write data
s_axi_wready_next = m_axi_wready_int_early;
if (s_axi_wr.wready && s_axi_wr.wvalid) begin
m_axi_wdata_int = {(M_BYTE_LANES/S_BYTE_LANES){s_axi_wr.wdata}};
m_axi_wstrb_int = 0;
m_axi_wstrb_int[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET] * S_STRB_W +: S_STRB_W] = s_axi_wr.wstrb;
m_axi_wlast_int = s_axi_wr.wlast;
m_axi_wuser_int = s_axi_wr.wuser;
m_axi_wvalid_int = 1'b1;
addr_next = addr_reg + (1 << burst_size_reg);
if (s_axi_wr.wlast) begin
s_axi_wready_next = 1'b0;
m_axi_bready_next = !s_axi_wr.bvalid;
state_next = STATE_RESP;
end else begin
state_next = STATE_DATA;
end
end else begin
state_next = STATE_DATA;
end
end
STATE_DATA_2: begin
s_axi_wready_next = m_axi_wready_int_early;
if (s_axi_wr.wready && s_axi_wr.wvalid) begin
if (CONVERT_NARROW_BURST) begin
for (integer i = 0; i < S_BYTE_LANES; i = i + 1) begin
if (s_axi_wr.wstrb[i]) begin
data_next[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET]*SEG_DATA_W+i*M_BYTE_SIZE +: M_BYTE_SIZE] = s_axi_wr.wdata[i*M_BYTE_SIZE +: M_BYTE_SIZE];
strb_next[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET]*SEG_STRB_W+i] = 1'b1;
end
end
end else begin
data_next[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET]*SEG_DATA_W +: SEG_DATA_W] = s_axi_wr.wdata;
strb_next[addr_reg[M_ADDR_BIT_OFFSET-1:S_ADDR_BIT_OFFSET]*SEG_STRB_W +: SEG_STRB_W] = s_axi_wr.wstrb;
end
m_axi_wdata_int = data_next;
m_axi_wstrb_int = strb_next;
m_axi_wlast_int = s_axi_wr.wlast;
m_axi_wuser_int = s_axi_wr.wuser;
burst_next = burst_reg - 1;
addr_next = addr_reg + (1 << burst_size_reg);
if (addr_next[CL_ADDR_W'(master_burst_size_reg)] != addr_reg[CL_ADDR_W'(master_burst_size_reg)]) begin
strb_next = '0;
m_axi_wvalid_int = 1'b1;
end
if (burst_reg == 0) begin
m_axi_wvalid_int = 1'b1;
s_axi_wready_next = 1'b0;
m_axi_bready_next = !s_axi_wr.bvalid;
state_next = STATE_RESP;
end else begin
state_next = STATE_DATA_2;
end
end else begin
state_next = STATE_DATA_2;
end
end
STATE_RESP: begin
// resp state; transfer write response
m_axi_bready_next = !s_axi_wr.bvalid;
if (m_axi_wr.bready && m_axi_wr.bvalid) begin
m_axi_bready_next = 1'b0;
s_axi_bid_next = id_reg;
s_axi_bresp_next = m_axi_wr.bresp;
s_axi_buser_next = m_axi_wr.buser;
s_axi_bvalid_next = 1'b1;
s_axi_awready_next = !m_axi_wr.awvalid;
state_next = STATE_IDLE;
end else begin
state_next = STATE_RESP;
end
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
id_reg <= id_next;
addr_reg <= addr_next;
data_reg <= data_next;
strb_reg <= strb_next;
wuser_reg <= wuser_next;
burst_reg <= burst_next;
burst_size_reg <= burst_size_next;
master_burst_size_reg <= master_burst_size_next;
burst_active_reg <= burst_active_next;
first_transfer_reg <= first_transfer_next;
s_axi_awready_reg <= s_axi_awready_next;
s_axi_wready_reg <= s_axi_wready_next;
s_axi_bid_reg <= s_axi_bid_next;
s_axi_bresp_reg <= s_axi_bresp_next;
s_axi_buser_reg <= s_axi_buser_next;
s_axi_bvalid_reg <= s_axi_bvalid_next;
m_axi_awid_reg <= m_axi_awid_next;
m_axi_awaddr_reg <= m_axi_awaddr_next;
m_axi_awlen_reg <= m_axi_awlen_next;
m_axi_awsize_reg <= m_axi_awsize_next;
m_axi_awburst_reg <= m_axi_awburst_next;
m_axi_awlock_reg <= m_axi_awlock_next;
m_axi_awcache_reg <= m_axi_awcache_next;
m_axi_awprot_reg <= m_axi_awprot_next;
m_axi_awqos_reg <= m_axi_awqos_next;
m_axi_awregion_reg <= m_axi_awregion_next;
m_axi_awuser_reg <= m_axi_awuser_next;
m_axi_awvalid_reg <= m_axi_awvalid_next;
m_axi_bready_reg <= m_axi_bready_next;
if (rst) begin
state_reg <= STATE_IDLE;
s_axi_awready_reg <= 1'b0;
s_axi_wready_reg <= 1'b0;
s_axi_bvalid_reg <= 1'b0;
m_axi_awvalid_reg <= 1'b0;
m_axi_bready_reg <= 1'b0;
end
end
// output datapath logic
logic [M_DATA_W-1:0] m_axi_wdata_reg = '0;
logic [M_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_axi_wvalid_reg = 1'b0, m_axi_wvalid_next;
logic [M_DATA_W-1:0] temp_m_axi_wdata_reg = '0;
logic [M_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 temp_m_axi_wvalid_reg = 1'b0, 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;
assign m_axi_wr.wdata = m_axi_wdata_reg;
assign m_axi_wr.wstrb = m_axi_wstrb_reg;
assign m_axi_wr.wlast = m_axi_wlast_reg;
assign m_axi_wr.wuser = WUSER_EN ? m_axi_wuser_reg : '0;
assign m_axi_wr.wvalid = m_axi_wvalid_reg;
// 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_wr.wready | (~temp_m_axi_wvalid_reg & (~m_axi_wvalid_reg | ~m_axi_wvalid_int));
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_wr.wready | ~m_axi_wvalid_reg) 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_wr.wready) begin
// input is not ready, but output is ready
m_axi_wvalid_next = temp_m_axi_wvalid_reg;
temp_m_axi_wvalid_next = 1'b0;
store_axi_w_temp_to_output = 1'b1;
end
end
always_ff @(posedge clk) begin
if (rst) begin
m_axi_wvalid_reg <= 1'b0;
m_axi_wready_int_reg <= 1'b0;
temp_m_axi_wvalid_reg <= 1'b0;
end else 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;
end
// 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
end
end else begin : downsize
// output is narrower; downsize
// output bus is wider
localparam EXPAND = M_BYTE_LANES > S_BYTE_LANES;
localparam DATA_W = EXPAND ? M_DATA_W : S_DATA_W;
localparam STRB_W = EXPAND ? M_STRB_W : S_STRB_W;
// required number of segments in wider bus
localparam SEG_COUNT = EXPAND ? (M_BYTE_LANES / S_BYTE_LANES) : (S_BYTE_LANES / M_BYTE_LANES);
// data width and keep width per segment
localparam SEG_DATA_W = DATA_W / SEG_COUNT;
localparam SEG_STRB_W = STRB_W / SEG_COUNT;
localparam [1:0]
STATE_IDLE = 2'd0,
STATE_DATA = 2'd1,
STATE_DATA_2 = 2'd2,
STATE_RESP = 2'd3;
logic [1:0] state_reg = STATE_IDLE, state_next;
logic [ID_W-1:0] id_reg = '0, id_next;
logic [ADDR_W-1:0] addr_reg = '0, addr_next;
logic [DATA_W-1:0] data_reg = '0, data_next;
logic [STRB_W-1:0] strb_reg = '0, strb_next;
logic [WUSER_W-1:0] wuser_reg = '0, wuser_next;
logic [7:0] burst_reg = '0, burst_next;
logic [2:0] burst_size_reg = '0, burst_size_next;
logic [7:0] master_burst_reg = '0, master_burst_next;
logic [2:0] master_burst_size_reg = '0, master_burst_size_next;
logic burst_active_reg = 1'b0, burst_active_next;
logic first_transfer_reg = 1'b0, first_transfer_next;
logic s_axi_awready_reg = 1'b0, s_axi_awready_next;
logic s_axi_wready_reg = 1'b0, s_axi_wready_next;
logic [ID_W-1:0] s_axi_bid_reg = '0, s_axi_bid_next;
logic [1:0] s_axi_bresp_reg = '0, s_axi_bresp_next;
logic [BUSER_W-1:0] s_axi_buser_reg = '0, s_axi_buser_next;
logic s_axi_bvalid_reg = 1'b0, s_axi_bvalid_next;
logic [ID_W-1:0] m_axi_awid_reg = '0, m_axi_awid_next;
logic [ADDR_W-1:0] m_axi_awaddr_reg = '0, m_axi_awaddr_next;
logic [7:0] m_axi_awlen_reg = '0, m_axi_awlen_next;
logic [2:0] m_axi_awsize_reg = '0, m_axi_awsize_next;
logic [1:0] m_axi_awburst_reg = '0, m_axi_awburst_next;
logic m_axi_awlock_reg = '0, m_axi_awlock_next;
logic [3:0] m_axi_awcache_reg = '0, m_axi_awcache_next;
logic [2:0] m_axi_awprot_reg = '0, m_axi_awprot_next;
logic [3:0] m_axi_awqos_reg = '0, m_axi_awqos_next;
logic [3:0] m_axi_awregion_reg = '0, m_axi_awregion_next;
logic [AWUSER_W-1:0] m_axi_awuser_reg = '0, m_axi_awuser_next;
logic m_axi_awvalid_reg = 1'b0, m_axi_awvalid_next;
logic m_axi_bready_reg = 1'b0, m_axi_bready_next;
// internal datapath
logic [M_DATA_W-1:0] m_axi_wdata_int;
logic [M_STRB_W-1:0] m_axi_wstrb_int;
logic m_axi_wlast_int;
logic [WUSER_W-1:0] m_axi_wuser_int;
logic m_axi_wvalid_int;
logic m_axi_wready_int_reg = 1'b0;
wire m_axi_wready_int_early;
assign s_axi_wr.awready = s_axi_awready_reg;
assign s_axi_wr.wready = s_axi_wready_reg;
assign s_axi_wr.bid = s_axi_bid_reg;
assign s_axi_wr.bresp = s_axi_bresp_reg;
assign s_axi_wr.buser = BUSER_EN ? s_axi_buser_reg : '0;
assign s_axi_wr.bvalid = s_axi_bvalid_reg;
assign m_axi_wr.awid = '0;
assign m_axi_wr.awaddr = m_axi_awaddr_reg;
assign m_axi_wr.awlen = m_axi_awlen_reg;
assign m_axi_wr.awsize = m_axi_awsize_reg;
assign m_axi_wr.awburst = m_axi_awburst_reg;
assign m_axi_wr.awlock = m_axi_awlock_reg;
assign m_axi_wr.awcache = m_axi_awcache_reg;
assign m_axi_wr.awprot = m_axi_awprot_reg;
assign m_axi_wr.awqos = m_axi_awqos_reg;
assign m_axi_wr.awregion = m_axi_awregion_reg;
assign m_axi_wr.awuser = AWUSER_EN ? m_axi_awuser_reg : '0;
assign m_axi_wr.awvalid = m_axi_awvalid_reg;
assign m_axi_wr.bready = m_axi_bready_reg;
always_comb begin
state_next = STATE_IDLE;
id_next = id_reg;
addr_next = addr_reg;
data_next = data_reg;
strb_next = strb_reg;
wuser_next = wuser_reg;
burst_next = burst_reg;
burst_size_next = burst_size_reg;
master_burst_next = master_burst_reg;
master_burst_size_next = master_burst_size_reg;
burst_active_next = burst_active_reg;
first_transfer_next = first_transfer_reg;
s_axi_awready_next = 1'b0;
s_axi_wready_next = 1'b0;
s_axi_bid_next = s_axi_bid_reg;
s_axi_bresp_next = s_axi_bresp_reg;
s_axi_buser_next = s_axi_buser_reg;
s_axi_bvalid_next = s_axi_bvalid_reg && !s_axi_wr.bready;
m_axi_awid_next = m_axi_awid_reg;
m_axi_awaddr_next = m_axi_awaddr_reg;
m_axi_awlen_next = m_axi_awlen_reg;
m_axi_awsize_next = m_axi_awsize_reg;
m_axi_awburst_next = m_axi_awburst_reg;
m_axi_awlock_next = m_axi_awlock_reg;
m_axi_awcache_next = m_axi_awcache_reg;
m_axi_awprot_next = m_axi_awprot_reg;
m_axi_awqos_next = m_axi_awqos_reg;
m_axi_awregion_next = m_axi_awregion_reg;
m_axi_awuser_next = m_axi_awuser_reg;
m_axi_awvalid_next = m_axi_awvalid_reg && !m_axi_wr.awready;
m_axi_bready_next = 1'b0;
m_axi_wdata_int = data_reg[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_DATA_W +: M_DATA_W];
m_axi_wstrb_int = strb_reg[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_STRB_W +: M_STRB_W];
m_axi_wlast_int = 1'b0;
m_axi_wuser_int = wuser_reg;
m_axi_wvalid_int = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state; wait for new burst
s_axi_awready_next = !m_axi_wr.awvalid;
first_transfer_next = 1'b1;
if (s_axi_wr.awready && s_axi_wr.awvalid) begin
s_axi_awready_next = 1'b0;
id_next = s_axi_wr.awid;
m_axi_awid_next = s_axi_wr.awid;
m_axi_awaddr_next = s_axi_wr.awaddr;
addr_next = s_axi_wr.awaddr;
burst_next = s_axi_wr.awlen;
burst_size_next = s_axi_wr.awsize;
burst_active_next = 1'b1;
if (s_axi_wr.awsize > M_BURST_SIZE) begin
// need to adjust burst size
if (s_axi_wr.awlen >> (8+M_BURST_SIZE-s_axi_wr.awsize) != 0) begin
// limit burst length to max
master_burst_next = 8'(32'hff << 3'(s_axi_wr.awsize-M_BURST_SIZE)) | 8'((8'(~s_axi_wr.awaddr) & 8'(8'hff >> (8-s_axi_wr.awsize))) >> M_BURST_SIZE);
end else begin
master_burst_next = 8'(s_axi_wr.awlen << 3'(s_axi_wr.awsize-M_BURST_SIZE)) | 8'((8'(~s_axi_wr.awaddr) & 8'(8'hff >> (8-s_axi_wr.awsize))) >> M_BURST_SIZE);
end
master_burst_size_next = M_BURST_SIZE;
m_axi_awlen_next = master_burst_next;
m_axi_awsize_next = master_burst_size_next;
end else begin
// pass through narrow (enough) burst
master_burst_next = s_axi_wr.awlen;
master_burst_size_next = s_axi_wr.awsize;
m_axi_awlen_next = s_axi_wr.awlen;
m_axi_awsize_next = s_axi_wr.awsize;
end
m_axi_awburst_next = s_axi_wr.awburst;
m_axi_awlock_next = s_axi_wr.awlock;
m_axi_awcache_next = s_axi_wr.awcache;
m_axi_awprot_next = s_axi_wr.awprot;
m_axi_awqos_next = s_axi_wr.awqos;
m_axi_awregion_next = s_axi_wr.awregion;
m_axi_awuser_next = s_axi_wr.awuser;
m_axi_awvalid_next = 1'b1;
s_axi_wready_next = m_axi_wready_int_early;
state_next = STATE_DATA;
end else begin
state_next = STATE_IDLE;
end
end
STATE_DATA: begin
s_axi_wready_next = m_axi_wready_int_early;
if (s_axi_wr.wready && s_axi_wr.wvalid) begin
data_next = s_axi_wr.wdata;
strb_next = s_axi_wr.wstrb;
wuser_next = s_axi_wr.wuser;
m_axi_wdata_int = s_axi_wr.wdata[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_DATA_W +: M_DATA_W];
m_axi_wstrb_int = s_axi_wr.wstrb[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_STRB_W +: M_STRB_W];
m_axi_wlast_int = 1'b0;
m_axi_wuser_int = s_axi_wr.wuser;
m_axi_wvalid_int = 1'b1;
burst_next = burst_reg - 1;
burst_active_next = burst_reg != 0;
master_burst_next = master_burst_reg - 1;
addr_next = (addr_reg + (1 << master_burst_size_reg)) & ({ADDR_W{1'b1}} << master_burst_size_reg);
if (master_burst_reg == 0) begin
s_axi_wready_next = 1'b0;
m_axi_bready_next = !s_axi_wr.bvalid && !s_axi_wr.awvalid;
m_axi_wlast_int = 1'b1;
state_next = STATE_RESP;
end else if (addr_next[CL_ADDR_W'(burst_size_reg)] != addr_reg[CL_ADDR_W'(burst_size_reg)]) begin
state_next = STATE_DATA;
end else begin
s_axi_wready_next = 1'b0;
state_next = STATE_DATA_2;
end
end else begin
state_next = STATE_DATA;
end
end
STATE_DATA_2: begin
s_axi_wready_next = 1'b0;
if (m_axi_wready_int_reg) begin
m_axi_wdata_int = data_reg[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_DATA_W +: M_DATA_W];
m_axi_wstrb_int = strb_reg[addr_reg[S_ADDR_BIT_OFFSET-1:M_ADDR_BIT_OFFSET] * M_STRB_W +: M_STRB_W];
m_axi_wlast_int = 1'b0;
m_axi_wuser_int = wuser_reg;
m_axi_wvalid_int = 1'b1;
master_burst_next = master_burst_reg - 1;
addr_next = (addr_reg + (1 << master_burst_size_reg)) & ({ADDR_W{1'b1}} << master_burst_size_reg);
if (master_burst_reg == 0) begin
// burst on master interface finished; transfer response
s_axi_wready_next = 1'b0;
m_axi_bready_next = !s_axi_wr.bvalid && !m_axi_wr.awvalid;
m_axi_wlast_int = 1'b1;
state_next = STATE_RESP;
end else if (addr_next[CL_ADDR_W'(burst_size_reg)] != addr_reg[CL_ADDR_W'(burst_size_reg)]) begin
state_next = STATE_DATA;
end else begin
s_axi_wready_next = 1'b0;
state_next = STATE_DATA_2;
end
end else begin
state_next = STATE_DATA_2;
end
end
STATE_RESP: begin
// resp state; transfer write response
m_axi_bready_next = !s_axi.bvalid && !m_axi.awvalid;
if (m_axi.bready && m_axi.bvalid) begin
first_transfer_next = 1'b0;
m_axi_bready_next = 1'b0;
s_axi_bid_next = id_reg;
if (first_transfer_reg || m_axi.bresp != 0) begin
s_axi_bresp_next = m_axi.bresp;
end
if (burst_reg >> (8+M_BURST_SIZE-burst_size_reg) != 0) begin
// limit burst length to max
master_burst_next = 8'd255;
end else begin
master_burst_next = (burst_reg << (burst_size_reg-M_BURST_SIZE)) | (8'hff >> (8-burst_size_reg) >> M_BURST_SIZE);
end
master_burst_size_next = M_BURST_SIZE;
m_axi_awaddr_next = addr_reg;
m_axi_awlen_next = master_burst_next;
m_axi_awsize_next = master_burst_size_next;
if (burst_active_reg) begin
// burst on slave interface still active; start new burst
m_axi_awvalid_next = 1'b1;
state_next = STATE_DATA;
end else begin
// burst on slave interface finished; return to idle
s_axi_bvalid_next = 1'b1;
s_axi_awready_next = !m_axi.awvalid;
state_next = STATE_IDLE;
end
end else begin
state_next = STATE_RESP;
end
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
id_reg <= id_next;
addr_reg <= addr_next;
data_reg <= data_next;
strb_reg <= strb_next;
wuser_reg <= wuser_next;
burst_reg <= burst_next;
burst_size_reg <= burst_size_next;
master_burst_reg <= master_burst_next;
master_burst_size_reg <= master_burst_size_next;
burst_active_reg <= burst_active_next;
first_transfer_reg <= first_transfer_next;
s_axi_awready_reg <= s_axi_awready_next;
s_axi_wready_reg <= s_axi_wready_next;
s_axi_bid_reg <= s_axi_bid_next;
s_axi_bresp_reg <= s_axi_bresp_next;
s_axi_buser_reg <= s_axi_buser_next;
s_axi_bvalid_reg <= s_axi_bvalid_next;
m_axi_awid_reg <= m_axi_awid_next;
m_axi_awaddr_reg <= m_axi_awaddr_next;
m_axi_awlen_reg <= m_axi_awlen_next;
m_axi_awsize_reg <= m_axi_awsize_next;
m_axi_awburst_reg <= m_axi_awburst_next;
m_axi_awlock_reg <= m_axi_awlock_next;
m_axi_awcache_reg <= m_axi_awcache_next;
m_axi_awprot_reg <= m_axi_awprot_next;
m_axi_awqos_reg <= m_axi_awqos_next;
m_axi_awregion_reg <= m_axi_awregion_next;
m_axi_awuser_reg <= m_axi_awuser_next;
m_axi_awvalid_reg <= m_axi_awvalid_next;
m_axi_bready_reg <= m_axi_bready_next;
if (rst) begin
state_reg <= STATE_IDLE;
s_axi_awready_reg <= 1'b0;
s_axi_wready_reg <= 1'b0;
s_axi_bvalid_reg <= 1'b0;
m_axi_awvalid_reg <= 1'b0;
m_axi_bready_reg <= 1'b0;
end
end
// output datapath logic
logic [M_DATA_W-1:0] m_axi_wdata_reg = '0;
logic [M_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_axi_wvalid_reg = 1'b0, m_axi_wvalid_next;
logic [M_DATA_W-1:0] temp_m_axi_wdata_reg = '0;
logic [M_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 temp_m_axi_wvalid_reg = 1'b0, 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;
assign m_axi_wr.wdata = m_axi_wdata_reg;
assign m_axi_wr.wstrb = m_axi_wstrb_reg;
assign m_axi_wr.wlast = m_axi_wlast_reg;
assign m_axi_wr.wuser = WUSER_EN ? m_axi_wuser_reg : '0;
assign m_axi_wr.wvalid = m_axi_wvalid_reg;
// 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_wr.wready | (~temp_m_axi_wvalid_reg & (~m_axi_wvalid_reg | ~m_axi_wvalid_int));
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_wr.wready | ~m_axi_wvalid_reg) 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_wr.wready) begin
// input is not ready, but output is ready
m_axi_wvalid_next = temp_m_axi_wvalid_reg;
temp_m_axi_wvalid_next = 1'b0;
store_axi_w_temp_to_output = 1'b1;
end
end
always_ff @(posedge clk) begin
if (rst) begin
m_axi_wvalid_reg <= 1'b0;
m_axi_wready_int_reg <= 1'b0;
temp_m_axi_wvalid_reg <= 1'b0;
end else 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;
end
// 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
end
end
endmodule
`resetall