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corundum/rtl/axi_dma_wr.v
2018-12-27 14:15:51 -08:00

862 lines
37 KiB
Verilog

/*
Copyright (c) 2018 Alex Forencich
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// Language: Verilog 2001
`timescale 1ns / 1ps
/*
* AXI4 DMA
*/
module axi_dma_wr #
(
parameter AXI_DATA_WIDTH = 32,
parameter AXI_ADDR_WIDTH = 16,
parameter AXI_STRB_WIDTH = (AXI_DATA_WIDTH/8),
parameter AXI_ID_WIDTH = 8,
parameter AXI_MAX_BURST_LEN = 16,
parameter AXIS_DATA_WIDTH = AXI_DATA_WIDTH,
parameter AXIS_KEEP_ENABLE = (AXIS_DATA_WIDTH>8),
parameter AXIS_KEEP_WIDTH = (AXIS_DATA_WIDTH/8),
parameter AXIS_LAST_ENABLE = 1,
parameter AXIS_ID_ENABLE = 0,
parameter AXIS_ID_WIDTH = 8,
parameter AXIS_DEST_ENABLE = 0,
parameter AXIS_DEST_WIDTH = 8,
parameter AXIS_USER_ENABLE = 1,
parameter AXIS_USER_WIDTH = 1,
parameter LEN_WIDTH = 20,
parameter TAG_WIDTH = 8,
parameter ENABLE_SG = 0,
parameter ENABLE_UNALIGNED = 0
)
(
input wire clk,
input wire rst,
/*
* AXI write descriptor input
*/
input wire [AXI_ADDR_WIDTH-1:0] s_axis_write_desc_addr,
input wire [LEN_WIDTH-1:0] s_axis_write_desc_len,
input wire [TAG_WIDTH-1:0] s_axis_write_desc_tag,
input wire s_axis_write_desc_valid,
output wire s_axis_write_desc_ready,
/*
* AXI write descriptor status output
*/
output wire [LEN_WIDTH-1:0] m_axis_write_desc_status_len,
output wire [TAG_WIDTH-1:0] m_axis_write_desc_status_tag,
output wire [AXIS_ID_WIDTH-1:0] m_axis_write_desc_status_id,
output wire [AXIS_DEST_WIDTH-1:0] m_axis_write_desc_status_dest,
output wire [AXIS_USER_WIDTH-1:0] m_axis_write_desc_status_user,
output wire m_axis_write_desc_status_valid,
/*
* AXI stream write data input
*/
input wire [AXIS_DATA_WIDTH-1:0] s_axis_write_data_tdata,
input wire [AXIS_KEEP_WIDTH-1:0] s_axis_write_data_tkeep,
input wire s_axis_write_data_tvalid,
output wire s_axis_write_data_tready,
input wire s_axis_write_data_tlast,
input wire [AXIS_ID_WIDTH-1:0] s_axis_write_data_tid,
input wire [AXIS_DEST_WIDTH-1:0] s_axis_write_data_tdest,
input wire [AXIS_USER_WIDTH-1:0] s_axis_write_data_tuser,
/*
* AXI master interface
*/
output wire [AXI_ID_WIDTH-1:0] m_axi_awid,
output wire [AXI_ADDR_WIDTH-1:0] m_axi_awaddr,
output wire [7:0] m_axi_awlen,
output wire [2:0] m_axi_awsize,
output wire [1:0] m_axi_awburst,
output wire m_axi_awlock,
output wire [3:0] m_axi_awcache,
output wire [2:0] m_axi_awprot,
output wire m_axi_awvalid,
input wire m_axi_awready,
output wire [AXI_DATA_WIDTH-1:0] m_axi_wdata,
output wire [AXI_STRB_WIDTH-1:0] m_axi_wstrb,
output wire m_axi_wlast,
output wire m_axi_wvalid,
input wire m_axi_wready,
input wire [AXI_ID_WIDTH-1:0] m_axi_bid,
input wire [1:0] m_axi_bresp,
input wire m_axi_bvalid,
output wire m_axi_bready,
/*
* Configuration
*/
input wire enable,
input wire abort
);
parameter AXI_WORD_WIDTH = AXI_STRB_WIDTH;
parameter AXI_WORD_SIZE = AXI_DATA_WIDTH/AXI_WORD_WIDTH;
parameter AXI_BURST_SIZE = $clog2(AXI_STRB_WIDTH);
parameter AXI_MAX_BURST_SIZE = AXI_MAX_BURST_LEN << AXI_BURST_SIZE;
parameter AXIS_KEEP_WIDTH_INT = AXIS_KEEP_ENABLE ? AXIS_KEEP_WIDTH : 1;
parameter AXIS_WORD_WIDTH = AXIS_KEEP_WIDTH_INT;
parameter AXIS_WORD_SIZE = AXIS_DATA_WIDTH/AXIS_WORD_WIDTH;
parameter OFFSET_WIDTH = AXI_STRB_WIDTH > 1 ? $clog2(AXI_STRB_WIDTH) : 1;
parameter OFFSET_MASK = AXI_STRB_WIDTH > 1 ? {OFFSET_WIDTH{1'b1}} : 0;
parameter ADDR_MASK = {AXI_ADDR_WIDTH{1'b1}} << $clog2(AXI_STRB_WIDTH);
parameter CYCLE_COUNT_WIDTH = LEN_WIDTH - AXI_BURST_SIZE + 1;
parameter STATUS_FIFO_ADDR_WIDTH = 5;
// bus width assertions
initial begin
if (AXI_WORD_SIZE * AXI_STRB_WIDTH != AXI_DATA_WIDTH) begin
$error("Error: AXI data width not evenly divisble");
$finish;
end
if (AXIS_WORD_SIZE * AXIS_KEEP_WIDTH_INT != AXIS_DATA_WIDTH) begin
$error("Error: AXI stream data width not evenly divisble");
$finish;
end
if (AXI_WORD_SIZE != AXIS_WORD_SIZE) begin
$error("Error: word size mismatch");
$finish;
end
if (2**$clog2(AXI_WORD_WIDTH) != AXI_WORD_WIDTH) begin
$error("Error: AXI word width must be even power of two");
$finish;
end
if (AXI_DATA_WIDTH != AXIS_DATA_WIDTH) begin
$error("Error: AXI interface width must match AXI stream interface width");
$finish;
end
if (AXI_MAX_BURST_LEN < 1 || AXI_MAX_BURST_LEN > 256) begin
$error("Error: AXI_MAX_BURST_LEN must be between 1 and 256");
$finish;
end
if (ENABLE_SG) begin
$error("Error: scatter/gather is not yet implemented");
$finish;
end
end
localparam [2:0]
STATE_IDLE = 3'd0,
STATE_START = 3'd1,
STATE_WRITE = 3'd2,
STATE_FINISH_BURST = 3'd3,
STATE_DROP_DATA = 3'd4;
reg [2:0] state_reg = STATE_IDLE, state_next;
// datapath control signals
reg transfer_in_save;
reg flush_save;
reg status_fifo_we;
integer i;
reg [OFFSET_WIDTH:0] cycle_size;
reg [AXI_ADDR_WIDTH-1:0] addr_reg = {AXI_ADDR_WIDTH{1'b0}}, addr_next;
reg [LEN_WIDTH-1:0] op_word_count_reg = {LEN_WIDTH{1'b0}}, op_word_count_next;
reg [LEN_WIDTH-1:0] tr_word_count_reg = {LEN_WIDTH{1'b0}}, tr_word_count_next;
reg [OFFSET_WIDTH-1:0] offset_reg = {OFFSET_WIDTH{1'b0}}, offset_next;
reg [OFFSET_WIDTH-1:0] last_cycle_offset_reg = {OFFSET_WIDTH{1'b0}}, last_cycle_offset_next;
reg [LEN_WIDTH-1:0] length_reg = {LEN_WIDTH{1'b0}}, length_next;
reg [CYCLE_COUNT_WIDTH-1:0] input_cycle_count_reg = {CYCLE_COUNT_WIDTH{1'b0}}, input_cycle_count_next;
reg [CYCLE_COUNT_WIDTH-1:0] output_cycle_count_reg = {CYCLE_COUNT_WIDTH{1'b0}}, output_cycle_count_next;
reg input_active_reg = 1'b0, input_active_next;
reg first_cycle_reg = 1'b0, first_cycle_next;
reg input_last_cycle_reg = 1'b0, input_last_cycle_next;
reg output_last_cycle_reg = 1'b0, output_last_cycle_next;
reg last_transfer_reg = 1'b0, last_transfer_next;
reg [TAG_WIDTH-1:0] tag_reg = {TAG_WIDTH{1'b0}}, tag_next;
reg [AXIS_ID_WIDTH-1:0] axis_id_reg = {AXIS_ID_WIDTH{1'b0}}, axis_id_next;
reg [AXIS_DEST_WIDTH-1:0] axis_dest_reg = {AXIS_DEST_WIDTH{1'b0}}, axis_dest_next;
reg [AXIS_USER_WIDTH-1:0] axis_user_reg = {AXIS_USER_WIDTH{1'b0}}, axis_user_next;
reg [STATUS_FIFO_ADDR_WIDTH+1-1:0] status_fifo_wr_ptr_reg = 0, status_fifo_wr_ptr_next;
reg [STATUS_FIFO_ADDR_WIDTH+1-1:0] status_fifo_rd_ptr_reg = 0, status_fifo_rd_ptr_next;
reg [LEN_WIDTH-1:0] status_fifo_len[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg [TAG_WIDTH-1:0] status_fifo_tag[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg [AXIS_ID_WIDTH-1:0] status_fifo_id[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg [AXIS_DEST_WIDTH-1:0] status_fifo_dest[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg [AXIS_USER_WIDTH-1:0] status_fifo_user[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg status_fifo_last[(2**STATUS_FIFO_ADDR_WIDTH)-1:0];
reg [LEN_WIDTH-1:0] status_fifo_wr_len;
reg [TAG_WIDTH-1:0] status_fifo_wr_tag;
reg [AXIS_ID_WIDTH-1:0] status_fifo_wr_id;
reg [AXIS_DEST_WIDTH-1:0] status_fifo_wr_dest;
reg [AXIS_USER_WIDTH-1:0] status_fifo_wr_user;
reg status_fifo_wr_last;
reg s_axis_write_desc_ready_reg = 1'b0, s_axis_write_desc_ready_next;
reg [LEN_WIDTH-1:0] m_axis_write_desc_status_len_reg = {LEN_WIDTH{1'b0}}, m_axis_write_desc_status_len_next;
reg [TAG_WIDTH-1:0] m_axis_write_desc_status_tag_reg = {TAG_WIDTH{1'b0}}, m_axis_write_desc_status_tag_next;
reg [AXIS_ID_WIDTH-1:0] m_axis_write_desc_status_id_reg = {AXIS_ID_WIDTH{1'b0}}, m_axis_write_desc_status_id_next;
reg [AXIS_DEST_WIDTH-1:0] m_axis_write_desc_status_dest_reg = {AXIS_DEST_WIDTH{1'b0}}, m_axis_write_desc_status_dest_next;
reg [AXIS_USER_WIDTH-1:0] m_axis_write_desc_status_user_reg = {AXIS_USER_WIDTH{1'b0}}, m_axis_write_desc_status_user_next;
reg m_axis_write_desc_status_valid_reg = 1'b0, m_axis_write_desc_status_valid_next;
reg [AXI_ADDR_WIDTH-1:0] m_axi_awaddr_reg = {AXI_ADDR_WIDTH{1'b0}}, m_axi_awaddr_next;
reg [7:0] m_axi_awlen_reg = 8'd0, m_axi_awlen_next;
reg m_axi_awvalid_reg = 1'b0, m_axi_awvalid_next;
reg m_axi_bready_reg = 1'b0, m_axi_bready_next;
reg s_axis_write_data_tready_reg = 1'b0, s_axis_write_data_tready_next;
reg [AXIS_DATA_WIDTH-1:0] save_axis_tdata_reg = {AXIS_DATA_WIDTH{1'b0}};
reg [AXIS_KEEP_WIDTH_INT-1:0] save_axis_tkeep_reg = {AXIS_KEEP_WIDTH_INT{1'b0}};
reg save_axis_tlast_reg = 1'b0;
reg [AXIS_DATA_WIDTH-1:0] shift_axis_tdata;
reg [AXIS_KEEP_WIDTH_INT-1:0] shift_axis_tkeep;
reg shift_axis_tvalid;
reg shift_axis_tlast;
reg shift_axis_input_tready;
reg shift_axis_extra_cycle;
// internal datapath
reg [AXI_DATA_WIDTH-1:0] m_axi_wdata_int;
reg [AXI_STRB_WIDTH-1:0] m_axi_wstrb_int;
reg m_axi_wlast_int;
reg m_axi_wvalid_int;
reg m_axi_wready_int_reg = 1'b0;
wire m_axi_wready_int_early;
assign s_axis_write_desc_ready = s_axis_write_desc_ready_reg;
assign m_axis_write_desc_status_len = m_axis_write_desc_status_len_reg;
assign m_axis_write_desc_status_tag = m_axis_write_desc_status_tag_reg;
assign m_axis_write_desc_status_id = m_axis_write_desc_status_id_reg;
assign m_axis_write_desc_status_dest = m_axis_write_desc_status_dest_reg;
assign m_axis_write_desc_status_user = m_axis_write_desc_status_user_reg;
assign m_axis_write_desc_status_valid = m_axis_write_desc_status_valid_reg;
assign s_axis_write_data_tready = s_axis_write_data_tready_reg;
assign m_axi_awid = {AXI_ID_WIDTH{1'b0}};
assign m_axi_awaddr = m_axi_awaddr_reg;
assign m_axi_awlen = m_axi_awlen_reg;
assign m_axi_awsize = AXI_BURST_SIZE;
assign m_axi_awburst = 2'b01;
assign m_axi_awlock = 1'b0;
assign m_axi_awcache = 4'b0011;
assign m_axi_awprot = 3'b010;
assign m_axi_awvalid = m_axi_awvalid_reg;
assign m_axi_bready = m_axi_bready_reg;
wire [AXI_ADDR_WIDTH-1:0] addr_plus_max_burst = addr_reg + AXI_MAX_BURST_SIZE;
wire [AXI_ADDR_WIDTH-1:0] addr_plus_count = addr_reg + op_word_count_reg;
always @* begin
shift_axis_extra_cycle = save_axis_tlast_reg & ((save_axis_tkeep_reg >> (AXIS_KEEP_WIDTH_INT-offset_reg)) != 0);
if (!ENABLE_UNALIGNED || offset_reg == 0) begin
// passthrough if no overlap
shift_axis_tdata = s_axis_write_data_tdata;
shift_axis_tkeep = s_axis_write_data_tkeep;
shift_axis_tvalid = s_axis_write_data_tvalid;
shift_axis_tlast = AXIS_LAST_ENABLE && s_axis_write_data_tlast;
shift_axis_input_tready = 1'b1;
end else if (!AXIS_LAST_ENABLE) begin
shift_axis_tdata = {s_axis_write_data_tdata, save_axis_tdata_reg} >> ((AXIS_KEEP_WIDTH_INT-offset_reg)*AXIS_WORD_SIZE);
shift_axis_tkeep = {s_axis_write_data_tkeep, save_axis_tkeep_reg} >> (AXIS_KEEP_WIDTH_INT-offset_reg);
shift_axis_tvalid = s_axis_write_data_tvalid;
shift_axis_tlast = 1'b0;
shift_axis_input_tready = 1'b1;
end else if (shift_axis_extra_cycle) begin
shift_axis_tdata = {s_axis_write_data_tdata, save_axis_tdata_reg} >> ((AXIS_KEEP_WIDTH_INT-offset_reg)*AXIS_WORD_SIZE);
shift_axis_tkeep = {{AXIS_KEEP_WIDTH_INT{1'b0}}, save_axis_tkeep_reg} >> (AXIS_KEEP_WIDTH_INT-offset_reg);
shift_axis_tvalid = 1'b1;
shift_axis_tlast = save_axis_tlast_reg;
shift_axis_input_tready = flush_save;
end else begin
shift_axis_tdata = {s_axis_write_data_tdata, save_axis_tdata_reg} >> ((AXIS_KEEP_WIDTH_INT-offset_reg)*AXIS_WORD_SIZE);
shift_axis_tkeep = {s_axis_write_data_tkeep, save_axis_tkeep_reg} >> (AXIS_KEEP_WIDTH_INT-offset_reg);
shift_axis_tvalid = s_axis_write_data_tvalid;
shift_axis_tlast = (s_axis_write_data_tlast && ((s_axis_write_data_tkeep >> (AXIS_KEEP_WIDTH_INT-offset_reg)) == 0));
shift_axis_input_tready = !(s_axis_write_data_tlast && s_axis_write_data_tvalid && transfer_in_save);
end
end
always @* begin
state_next = STATE_IDLE;
s_axis_write_desc_ready_next = 1'b0;
m_axis_write_desc_status_len_next = m_axis_write_desc_status_len_reg;
m_axis_write_desc_status_tag_next = m_axis_write_desc_status_tag_reg;
m_axis_write_desc_status_id_next = m_axis_write_desc_status_id_reg;
m_axis_write_desc_status_dest_next = m_axis_write_desc_status_dest_reg;
m_axis_write_desc_status_user_next = m_axis_write_desc_status_user_reg;
m_axis_write_desc_status_valid_next = 1'b0;
s_axis_write_data_tready_next = 1'b0;
m_axi_awaddr_next = m_axi_awaddr_reg;
m_axi_awlen_next = m_axi_awlen_reg;
m_axi_awvalid_next = m_axi_awvalid_reg && !m_axi_awready;
m_axi_wdata_int = shift_axis_tdata;
m_axi_wstrb_int = shift_axis_tkeep;
m_axi_wlast_int = 1'b0;
m_axi_wvalid_int = 1'b0;
m_axi_bready_next = 1'b0;
transfer_in_save = 1'b0;
flush_save = 1'b0;
status_fifo_we = 1'b0;
cycle_size = AXIS_KEEP_WIDTH_INT;
addr_next = addr_reg;
offset_next = offset_reg;
last_cycle_offset_next = last_cycle_offset_reg;
length_next = length_reg;
op_word_count_next = op_word_count_reg;
tr_word_count_next = tr_word_count_reg;
input_cycle_count_next = input_cycle_count_reg;
output_cycle_count_next = output_cycle_count_reg;
input_active_next = input_active_reg;
first_cycle_next = first_cycle_reg;
input_last_cycle_next = input_last_cycle_reg;
output_last_cycle_next = output_last_cycle_reg;
last_transfer_next = last_transfer_reg;
status_fifo_rd_ptr_next = status_fifo_rd_ptr_reg;
tag_next = tag_reg;
axis_id_next = axis_id_reg;
axis_dest_next = axis_dest_reg;
axis_user_next = axis_user_reg;
status_fifo_wr_len = length_reg;
status_fifo_wr_tag = tag_reg;
status_fifo_wr_id = axis_id_reg;
status_fifo_wr_dest = axis_dest_reg;
status_fifo_wr_user = axis_user_reg;
status_fifo_wr_last = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state - load new descriptor to start operation
flush_save = 1'b1;
s_axis_write_desc_ready_next = enable;
if (ENABLE_UNALIGNED) begin
addr_next = s_axis_write_desc_addr;
offset_next = s_axis_write_desc_addr & OFFSET_MASK;
last_cycle_offset_next = offset_next + (s_axis_write_desc_len & OFFSET_MASK);
end else begin
addr_next = s_axis_write_desc_addr & ADDR_MASK;
offset_next = 0;
last_cycle_offset_next = offset_next + (s_axis_write_desc_len & OFFSET_MASK);
end
tag_next = s_axis_write_desc_tag;
op_word_count_next = s_axis_write_desc_len;
first_cycle_next = 1'b1;
length_next = 0;
if (s_axis_write_desc_ready && s_axis_write_desc_valid) begin
s_axis_write_desc_ready_next = 1'b0;
state_next = STATE_START;
end else begin
state_next = STATE_IDLE;
end
end
STATE_START: begin
// start state - initiate new AXI transfer
if (op_word_count_reg <= AXI_MAX_BURST_SIZE - (addr_reg & OFFSET_MASK)) begin
// packet smaller than max burst size
if (addr_reg[12] != addr_plus_count[12]) begin
// crosses 4k boundary
tr_word_count_next = 13'h1000 - addr_reg[11:0];
end else begin
// does not cross 4k boundary
tr_word_count_next = op_word_count_reg;
end
end else begin
// packet larger than max burst size
if (addr_reg[12] != addr_plus_max_burst[12]) begin
// crosses 4k boundary
tr_word_count_next = 13'h1000 - addr_reg[11:0];
end else begin
// does not cross 4k boundary
tr_word_count_next = AXI_MAX_BURST_SIZE - (addr_reg & OFFSET_MASK);
end
end
input_cycle_count_next = (tr_word_count_next - 1) >> $clog2(AXIS_KEEP_WIDTH_INT);
input_last_cycle_next = input_cycle_count_next == 0;
if (ENABLE_UNALIGNED) begin
output_cycle_count_next = (tr_word_count_next + (addr_reg & OFFSET_MASK) - 1) >> AXI_BURST_SIZE;
end else begin
output_cycle_count_next = (tr_word_count_next - 1) >> AXI_BURST_SIZE;
end
output_last_cycle_next = output_cycle_count_next == 0;
last_transfer_next = tr_word_count_next == op_word_count_reg;
input_active_next = 1'b1;
if (ENABLE_UNALIGNED) begin
if (!first_cycle_reg && last_transfer_next) begin
if (offset_reg >= last_cycle_offset_reg && last_cycle_offset_reg > 0) begin
// last cycle will be served by stored partial cycle
input_active_next = input_cycle_count_next > 0;
input_cycle_count_next = input_cycle_count_next - 1;
end
end
end
m_axi_awaddr_next = addr_reg;
m_axi_awlen_next = output_cycle_count_next;
m_axi_awvalid_next = s_axis_write_data_tvalid || !first_cycle_reg;
if (m_axi_awvalid_next) begin
addr_next = addr_reg + tr_word_count_next;
op_word_count_next = op_word_count_reg - tr_word_count_next;
s_axis_write_data_tready_next = m_axi_wready_int_early && input_active_next;
state_next = STATE_WRITE;
end else begin
state_next = STATE_START;
end
end
STATE_WRITE: begin
s_axis_write_data_tready_next = m_axi_wready_int_early && (last_transfer_reg || input_active_reg) && shift_axis_input_tready;
if (m_axi_wready_int_reg && ((s_axis_write_data_tready && shift_axis_tvalid) || (!input_active_reg && !last_transfer_reg) || !shift_axis_input_tready)) begin
if (s_axis_write_data_tready && s_axis_write_data_tvalid) begin
transfer_in_save = 1'b1;
axis_id_next = s_axis_write_data_tid;
axis_dest_next = s_axis_write_data_tdest;
axis_user_next = s_axis_write_data_tuser;
end
// update counters
if (first_cycle_reg) begin
length_next = length_reg + (AXIS_KEEP_WIDTH_INT - offset_reg);
end else begin
length_next = length_reg + AXIS_KEEP_WIDTH_INT;
end
if (input_active_reg) begin
input_cycle_count_next = input_cycle_count_reg - 1;
input_active_next = input_cycle_count_reg > 0;
end
input_last_cycle_next = input_cycle_count_next == 0;
output_cycle_count_next = output_cycle_count_reg - 1;
output_last_cycle_next = output_cycle_count_next == 0;
first_cycle_next = 1'b0;
m_axi_wdata_int = shift_axis_tdata;
if (first_cycle_reg) begin
m_axi_wstrb_int = {AXI_STRB_WIDTH{1'b1}} << offset_reg;
end else begin
m_axi_wstrb_int = {AXI_STRB_WIDTH{1'b1}};
end
m_axi_wvalid_int = 1'b1;
if (AXIS_LAST_ENABLE && shift_axis_tlast) begin
// end of data packet
if (AXIS_KEEP_ENABLE) begin
cycle_size = AXIS_KEEP_WIDTH_INT;
for (i = AXIS_KEEP_WIDTH_INT; i >= 0; i = i - 1) begin
if (!shift_axis_tkeep[i] && (!first_cycle_reg || i >= offset_reg)) begin
cycle_size = i;
end
end
end else begin
cycle_size = AXIS_KEEP_WIDTH_INT;
end
if (output_last_cycle_reg) begin
m_axi_wlast_int = 1'b1;
// no more data to transfer, finish operation
if (last_transfer_reg && last_cycle_offset_reg > 0) begin
if (AXIS_KEEP_ENABLE && cycle_size < last_cycle_offset_reg) begin
m_axi_wstrb_int = m_axi_wstrb_int & {AXI_STRB_WIDTH{1'b1}} >> (AXI_STRB_WIDTH - cycle_size);
if (first_cycle_reg) begin
length_next = length_reg + (cycle_size - offset_reg);
end else begin
length_next = length_reg + cycle_size;
end
end else begin
m_axi_wstrb_int = m_axi_wstrb_int & {AXI_STRB_WIDTH{1'b1}} >> (AXI_STRB_WIDTH - last_cycle_offset_reg);
if (first_cycle_reg) begin
length_next = length_reg + (last_cycle_offset_reg - offset_reg);
end else begin
length_next = length_reg + last_cycle_offset_reg;
end
end
end else begin
if (AXIS_KEEP_ENABLE && cycle_size < AXI_STRB_WIDTH) begin
m_axi_wstrb_int = m_axi_wstrb_int & {AXI_STRB_WIDTH{1'b1}} >> (AXI_STRB_WIDTH - cycle_size);
if (first_cycle_reg) begin
length_next = length_reg + (cycle_size - offset_reg);
end else begin
length_next = length_reg + cycle_size;
end
end
end
// enqueue status FIFO entry for write completion
status_fifo_we = 1'b1;
status_fifo_wr_len = length_next;
status_fifo_wr_tag = tag_reg;
status_fifo_wr_id = axis_id_next;
status_fifo_wr_dest = axis_dest_next;
status_fifo_wr_user = axis_user_next;
status_fifo_wr_last = 1'b1;
s_axis_write_data_tready_next = 1'b0;
s_axis_write_desc_ready_next = enable;
state_next = STATE_IDLE;
end else begin
// more cycles left in burst, finish burst
if (AXIS_KEEP_ENABLE && cycle_size < AXI_STRB_WIDTH) begin
m_axi_wstrb_int = m_axi_wstrb_int & {AXI_STRB_WIDTH{1'b1}} >> (AXI_STRB_WIDTH - cycle_size);
if (first_cycle_reg) begin
length_next = length_reg + (cycle_size - offset_reg);
end else begin
length_next = length_reg + cycle_size;
end
end
// enqueue status FIFO entry for write completion
status_fifo_we = 1'b1;
status_fifo_wr_len = length_next;
status_fifo_wr_tag = tag_reg;
status_fifo_wr_id = axis_id_next;
status_fifo_wr_dest = axis_dest_next;
status_fifo_wr_user = axis_user_next;
status_fifo_wr_last = 1'b1;
s_axis_write_data_tready_next = 1'b0;
state_next = STATE_FINISH_BURST;
end
end else if (output_last_cycle_reg) begin
m_axi_wlast_int = 1'b1;
if (op_word_count_reg > 0) begin
// current AXI transfer complete, but there is more data to transfer
// enqueue status FIFO entry for write completion
status_fifo_we = 1'b1;
status_fifo_wr_len = length_next;
status_fifo_wr_tag = tag_reg;
status_fifo_wr_id = axis_id_next;
status_fifo_wr_dest = axis_dest_next;
status_fifo_wr_user = axis_user_next;
status_fifo_wr_last = 1'b0;
s_axis_write_data_tready_next = 1'b0;
state_next = STATE_START;
end else begin
// no more data to transfer, finish operation
if (last_cycle_offset_reg > 0) begin
m_axi_wstrb_int = m_axi_wstrb_int & {AXI_STRB_WIDTH{1'b1}} >> (AXI_STRB_WIDTH - last_cycle_offset_reg);
if (first_cycle_reg) begin
length_next = length_reg + (last_cycle_offset_reg - offset_reg);
end else begin
length_next = length_reg + last_cycle_offset_reg;
end
end
// enqueue status FIFO entry for write completion
status_fifo_we = 1'b1;
status_fifo_wr_len = length_next;
status_fifo_wr_tag = tag_reg;
status_fifo_wr_id = axis_id_next;
status_fifo_wr_dest = axis_dest_next;
status_fifo_wr_user = axis_user_next;
status_fifo_wr_last = 1'b1;
if (AXIS_LAST_ENABLE) begin
// not at the end of packet; drop remainder
s_axis_write_data_tready_next = shift_axis_input_tready;
state_next = STATE_DROP_DATA;
end else begin
// no framing; return to idle
s_axis_write_data_tready_next = 1'b0;
s_axis_write_desc_ready_next = enable;
state_next = STATE_IDLE;
end
end
end else begin
s_axis_write_data_tready_next = m_axi_wready_int_early && (last_transfer_reg || input_active_next) && shift_axis_input_tready;
state_next = STATE_WRITE;
end
end else begin
state_next = STATE_WRITE;
end
end
STATE_FINISH_BURST: begin
// finish current AXI burst
if (m_axi_wready_int_reg) begin
// update counters
if (input_active_reg) begin
input_cycle_count_next = input_cycle_count_reg - 1;
input_active_next = input_cycle_count_reg > 0;
end
input_last_cycle_next = input_cycle_count_next == 0;
output_cycle_count_next = output_cycle_count_reg - 1;
output_last_cycle_next = output_cycle_count_next == 0;
m_axi_wdata_int = {AXI_DATA_WIDTH{1'b0}};
m_axi_wstrb_int = {AXI_STRB_WIDTH{1'b0}};
m_axi_wvalid_int = 1'b1;
if (output_last_cycle_reg) begin
// no more data to transfer, finish operation
m_axi_wlast_int = 1'b1;
s_axis_write_data_tready_next = 1'b0;
s_axis_write_desc_ready_next = enable;
state_next = STATE_IDLE;
end else begin
// more cycles in AXI transfer
state_next = STATE_FINISH_BURST;
end
end else begin
state_next = STATE_FINISH_BURST;
end
end
STATE_DROP_DATA: begin
// drop excess AXI stream data
s_axis_write_data_tready_next = shift_axis_input_tready;
if (shift_axis_tvalid) begin
if (s_axis_write_data_tready && s_axis_write_data_tvalid) begin
transfer_in_save = 1'b1;
end
if (shift_axis_tlast) begin
s_axis_write_data_tready_next = 1'b0;
s_axis_write_desc_ready_next = enable;
state_next = STATE_IDLE;
end else begin
state_next = STATE_DROP_DATA;
end
end else begin
state_next = STATE_DROP_DATA;
end
end
endcase
if (status_fifo_rd_ptr_reg != status_fifo_wr_ptr_reg) begin
// status FIFO not empty
if (m_axi_bready && m_axi_bvalid) begin
// got write completion, pop and return status
m_axis_write_desc_status_len_next = status_fifo_len[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
m_axis_write_desc_status_tag_next = status_fifo_tag[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
m_axis_write_desc_status_id_next = status_fifo_id[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
m_axis_write_desc_status_dest_next = status_fifo_dest[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
m_axis_write_desc_status_user_next = status_fifo_user[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
m_axis_write_desc_status_valid_next = status_fifo_last[status_fifo_rd_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]];
status_fifo_rd_ptr_next = status_fifo_rd_ptr_reg + 1;
m_axi_bready_next = 1'b0;
end else begin
// wait for write completion
m_axi_bready_next = 1'b1;
end
end
end
always @(posedge clk) begin
if (rst) begin
state_reg <= STATE_IDLE;
s_axis_write_desc_ready_reg <= 1'b0;
m_axis_write_desc_status_valid_reg <= 1'b0;
s_axis_write_data_tready_reg <= 1'b0;
m_axi_awvalid_reg <= 1'b0;
m_axi_bready_reg <= 1'b0;
save_axis_tlast_reg <= 1'b0;
status_fifo_wr_ptr_reg <= 0;
status_fifo_rd_ptr_reg <= 0;
end else begin
state_reg <= state_next;
s_axis_write_desc_ready_reg <= s_axis_write_desc_ready_next;
m_axis_write_desc_status_valid_reg <= m_axis_write_desc_status_valid_next;
s_axis_write_data_tready_reg <= s_axis_write_data_tready_next;
m_axi_awvalid_reg <= m_axi_awvalid_next;
m_axi_bready_reg <= m_axi_bready_next;
// datapath
if (flush_save) begin
save_axis_tlast_reg <= 1'b0;
end else if (transfer_in_save) begin
save_axis_tlast_reg <= s_axis_write_data_tlast;
end
if (status_fifo_we) begin
status_fifo_wr_ptr_reg <= status_fifo_wr_ptr_reg + 1;
end
status_fifo_rd_ptr_reg <= status_fifo_rd_ptr_next;
end
m_axis_write_desc_status_len_reg <= m_axis_write_desc_status_len_next;
m_axis_write_desc_status_tag_reg <= m_axis_write_desc_status_tag_next;
m_axis_write_desc_status_id_reg <= m_axis_write_desc_status_id_next;
m_axis_write_desc_status_dest_reg <= m_axis_write_desc_status_dest_next;
m_axis_write_desc_status_user_reg <= m_axis_write_desc_status_user_next;
m_axi_awaddr_reg <= m_axi_awaddr_next;
m_axi_awlen_reg <= m_axi_awlen_next;
addr_reg <= addr_next;
offset_reg <= offset_next;
last_cycle_offset_reg <= last_cycle_offset_next;
length_reg <= length_next;
op_word_count_reg <= op_word_count_next;
tr_word_count_reg <= tr_word_count_next;
input_cycle_count_reg <= input_cycle_count_next;
output_cycle_count_reg <= output_cycle_count_next;
input_active_reg <= input_active_next;
first_cycle_reg <= first_cycle_next;
input_last_cycle_reg <= input_last_cycle_next;
output_last_cycle_reg <= output_last_cycle_next;
last_transfer_reg <= last_transfer_next;
tag_reg <= tag_next;
axis_id_reg <= axis_id_next;
axis_dest_reg <= axis_dest_next;
axis_user_reg <= axis_user_next;
if (flush_save) begin
save_axis_tkeep_reg <= {AXIS_KEEP_WIDTH_INT{1'b0}};
end else if (transfer_in_save) begin
save_axis_tdata_reg <= s_axis_write_data_tdata;
save_axis_tkeep_reg <= AXIS_KEEP_ENABLE ? s_axis_write_data_tkeep : {AXIS_KEEP_WIDTH_INT{1'b1}};
end
if (status_fifo_we) begin
status_fifo_len[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_len;
status_fifo_tag[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_tag;
status_fifo_id[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_id;
status_fifo_dest[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_dest;
status_fifo_user[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_user;
status_fifo_last[status_fifo_wr_ptr_reg[STATUS_FIFO_ADDR_WIDTH-1:0]] <= status_fifo_wr_last;
status_fifo_wr_ptr_reg <= status_fifo_wr_ptr_reg + 1;
end
end
// output datapath logic
reg [AXI_DATA_WIDTH-1:0] m_axi_wdata_reg = {AXI_DATA_WIDTH{1'b0}};
reg [AXI_STRB_WIDTH-1:0] m_axi_wstrb_reg = {AXI_STRB_WIDTH{1'b0}};
reg m_axi_wlast_reg = 1'b0;
reg m_axi_wvalid_reg = 1'b0, m_axi_wvalid_next;
reg [AXI_DATA_WIDTH-1:0] temp_m_axi_wdata_reg = {AXI_DATA_WIDTH{1'b0}};
reg [AXI_STRB_WIDTH-1:0] temp_m_axi_wstrb_reg = {AXI_STRB_WIDTH{1'b0}};
reg temp_m_axi_wlast_reg = 1'b0;
reg temp_m_axi_wvalid_reg = 1'b0, temp_m_axi_wvalid_next;
// datapath control
reg store_axi_w_int_to_output;
reg store_axi_w_int_to_temp;
reg store_axi_w_temp_to_output;
assign m_axi_wdata = m_axi_wdata_reg;
assign m_axi_wstrb = m_axi_wstrb_reg;
assign m_axi_wvalid = m_axi_wvalid_reg;
assign m_axi_wlast = m_axi_wlast_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_wready || (!temp_m_axi_wvalid_reg && (!m_axi_wvalid_reg || !m_axi_wvalid_int));
always @* 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) 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) 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 @(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;
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;
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;
end
end
endmodule