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util_axis_fifo: Add TKEEP support
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@Csomi
Istvan Csomortani authored and Csomi committed Mar 8, 2021
1 parent 0d3d099 commit 9611be9
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Showing 2 changed files with 102 additions and 21 deletions.
119 changes: 100 additions & 19 deletions library/util_axis_fifo/util_axis_fifo.v
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Original file line number Diff line number Diff line change
Expand Up @@ -40,13 +40,16 @@ module util_axis_fifo #(
parameter ASYNC_CLK = 1,
parameter M_AXIS_REGISTERED = 1,
parameter [ADDRESS_WIDTH-1:0] ALMOST_EMPTY_THRESHOLD = 16,
parameter [ADDRESS_WIDTH-1:0] ALMOST_FULL_THRESHOLD = 16
parameter [ADDRESS_WIDTH-1:0] ALMOST_FULL_THRESHOLD = 16,
parameter TLAST_EN = 0,
parameter TKEEP_EN = 0
) (
input m_axis_aclk,
input m_axis_aresetn,
input m_axis_ready,
output m_axis_valid,
output [DATA_WIDTH-1:0] m_axis_data,
output [DATA_WIDTH/8-1:0] m_axis_tkeep,
output m_axis_tlast,
output [ADDRESS_WIDTH-1:0] m_axis_level,
output m_axis_empty,
Expand All @@ -57,18 +60,26 @@ module util_axis_fifo #(
output s_axis_ready,
input s_axis_valid,
input [DATA_WIDTH-1:0] s_axis_data,
input [DATA_WIDTH/8-1:0] s_axis_tkeep,
input s_axis_tlast,
output [ADDRESS_WIDTH-1:0] s_axis_room,
output s_axis_full,
output s_axis_almost_full
);

localparam MEM_WORD = (TKEEP_EN & TLAST_EN) ? (DATA_WIDTH+DATA_WIDTH/8+1) :
(TKEEP_EN) ? (DATA_WIDTH+DATA_WIDTH/8) :
(TLAST_EN) ? (DATA_WIDTH+1) :
(DATA_WIDTH);

wire [MEM_WORD-1:0] s_axis_data_int_s;
wire [MEM_WORD-1:0] m_axis_data_int_s;

generate if (ADDRESS_WIDTH == 0) begin : zerodeep /* it's not a real FIFO, just a 1 stage pipeline */

if (ASYNC_CLK) begin

(* KEEP = "yes" *) reg [DATA_WIDTH-1:0] cdc_sync_fifo_ram;
reg axis_tlast_d;
reg s_axis_waddr = 1'b0;
reg m_axis_raddr = 1'b0;

Expand Down Expand Up @@ -107,7 +118,6 @@ generate if (ADDRESS_WIDTH == 0) begin : zerodeep /* it's not a real FIFO, just
always @(posedge s_axis_aclk) begin
if (s_axis_ready == 1'b1 && s_axis_valid == 1'b1)
cdc_sync_fifo_ram <= s_axis_data;
axis_tlast_d <= s_axis_tlast;
end

always @(posedge s_axis_aclk) begin
Expand All @@ -128,31 +138,55 @@ generate if (ADDRESS_WIDTH == 0) begin : zerodeep /* it's not a real FIFO, just
end

assign m_axis_data = cdc_sync_fifo_ram;
assign m_axis_tlast = axis_tlast_d;

end else begin /* !ASYNC_CLK */
// TLAST support
if (TLAST_EN) begin

reg axis_tlast_d;

always @(posedge s_axis_aclk) begin
if (s_axis_ready == 1'b1 && s_axis_valid == 1'b1)
axis_tlast_d <= s_axis_tlast;
end
assign m_axis_tlast = axis_tlast_d;

end

// TKEEP support
if (TKEEP_EN) begin

reg axis_tkeep_d;

always @(posedge s_axis_aclk) begin
if (s_axis_ready == 1'b1 && s_axis_valid == 1'b1)
axis_tkeep_d <= s_axis_tkeep;
end
assign m_axis_tkeep = axis_tkeep_d;

end


end /* zerodeep */
else
begin /* !ASYNC_CLK */

// Note: In this mode, the write and read interface must have a symmetric
// aspect ratio
reg [DATA_WIDTH-1:0] axis_data_d;
reg axis_valid_d;
reg axis_tlast_d;

always @(posedge s_axis_aclk) begin
if (!s_axis_aresetn) begin
axis_data_d <= {DATA_WIDTH{1'b0}};
axis_valid_d <= 1'b0;
axis_tlast_d <= 1'b0;
end else if (s_axis_ready) begin
axis_data_d <= s_axis_data;
axis_valid_d <= s_axis_valid;
axis_tlast_d <= s_axis_tlast;
end
end

assign m_axis_data = axis_data_d;
assign m_axis_valid = axis_valid_d;
assign m_axis_tlast = axis_tlast_d;
assign s_axis_ready = m_axis_ready | ~m_axis_valid;
assign m_axis_empty = 1'b0;
assign m_axis_almost_empty = 1'b0;
Expand All @@ -161,7 +195,36 @@ generate if (ADDRESS_WIDTH == 0) begin : zerodeep /* it's not a real FIFO, just
assign s_axis_almost_full = 1'b0;
assign s_axis_room = 1'b0;

end
// TLAST support
if (TLAST_EN) begin
reg axis_tlast_d;

always @(posedge s_axis_aclk) begin
if (!s_axis_aresetn) begin
axis_tlast_d <= 1'b0;
end else if (s_axis_ready) begin
axis_tlast_d <= s_axis_tlast;
end
end
assign m_axis_tlast = axis_tlast_d;
end

// TKEEP support
if (TKEEP_EN) begin
reg axis_tkeep_d;

always @(posedge s_axis_aclk) begin
if (!s_axis_aresetn) begin
axis_tkeep_d <= 1'b0;
end else if (s_axis_ready) begin
axis_tkeep_d <= s_axis_tkeep;
end
end
assign m_axis_tkeep = axis_tkeep_d;

end

end /* !ASYNC_CLK */

end else begin : fifo /* ADDRESS_WIDTH != 0 - this is a real FIFO implementation */

Expand Down Expand Up @@ -214,59 +277,77 @@ end else begin : fifo /* ADDRESS_WIDTH != 0 - this is a real FIFO implementation
.s_axis_room(s_axis_room)
);

// TLAST and TKEEP support
if (TLAST_EN & TKEEP_EN) begin
assign s_axis_data_int_s = {s_axis_tkeep, s_axis_tlast, s_axis_data};
assign m_axis_tkeep = m_axis_data_int_s[MEM_WORD-1-:DATA_WIDTH/8];
assign m_axis_tlast = m_axis_data_int_s[DATA_WIDTH];
assign m_axis_data = m_axis_data_int_s[DATA_WIDTH-1:0];
end else if (TKEEP_EN) begin
assign s_axis_data_int_s = {s_axis_tkeep, s_axis_data};
assign m_axis_tkeep = m_axis_data_int_s[MEM_WORD-1-:DATA_WIDTH/8];
assign m_axis_data = m_axis_data_int_s[DATA_WIDTH-1:0];
end else if (TLAST_EN) begin
assign s_axis_data_int_s = {s_axis_tlast, s_axis_data};
assign m_axis_tlast = m_axis_data_int_s[DATA_WIDTH];
assign m_axis_data = m_axis_data_int_s[DATA_WIDTH-1:0];
end else begin
assign s_axis_data_int_s = {s_axis_data};
assign m_axis_data = m_axis_data_int_s[DATA_WIDTH-1:0];
end

if (ASYNC_CLK == 1) begin : async_clocks /* Asynchronous WRITE/READ clocks */

// The assumption is that in this mode the M_AXIS_REGISTERED is 1
// When the clocks are asynchronous instantiate a block RAM
// regardless of the requested size to make sure we threat the
// clock crossing correctly
ad_mem #(
.DATA_WIDTH (DATA_WIDTH+1),
.DATA_WIDTH (MEM_WORD),
.ADDRESS_WIDTH (ADDRESS_WIDTH))
i_mem (
.clka(s_axis_aclk),
.wea(s_mem_write),
.addra(s_axis_waddr),
.dina({s_axis_tlast, s_axis_data}),
.dina(s_axis_data_int_s),
.clkb(m_axis_aclk),
.reb(m_mem_read),
.addrb(m_axis_raddr),
.doutb({m_axis_tlast, m_axis_data})
.doutb(m_axis_data_int_s)
);

assign _m_axis_ready = ~valid || m_axis_ready;
assign m_axis_valid = valid;

end else begin : sync_clocks /* Synchronous WRITE/READ clocks */

reg [DATA_WIDTH:0] ram[0:2**ADDRESS_WIDTH-1];
reg [MEM_WORD-1:0] ram[0:2**ADDRESS_WIDTH-1];

// When the clocks are synchronous use behavioral modeling for the SDP RAM
// Let the synthesizer decide what to infer (distributed or block RAM)
always @(posedge s_axis_aclk) begin
if (s_mem_write)
ram[s_axis_waddr] <= {s_axis_tlast, s_axis_data};
ram[s_axis_waddr] <= s_axis_data_int_s;
end

if (M_AXIS_REGISTERED == 1) begin

reg [DATA_WIDTH:0] data;
reg [MEM_WORD-1:0] data;

always @(posedge m_axis_aclk) begin
if (m_mem_read)
data <= ram[m_axis_raddr];
end

assign _m_axis_ready = ~valid || m_axis_ready;
assign m_axis_data = data[DATA_WIDTH-1:0];
assign m_axis_tlast = data[DATA_WIDTH];
assign m_axis_data_int_s = data;
assign m_axis_valid = valid;

end else begin

assign _m_axis_ready = m_axis_ready;
assign m_axis_valid = _m_axis_valid;
assign {m_axis_tlast, m_axis_data} = ram[m_axis_raddr];
assign m_axis_data_int_s = ram[m_axis_raddr];

end
end
Expand Down
4 changes: 2 additions & 2 deletions library/util_axis_fifo/util_axis_fifo_address_generator.v
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,7 @@ wire [ADDRESS_WIDTH-1:0] m_axis_level_s;
// Write address counter
//------------------------------------------------------------------------------

assign s_axis_write_s = s_axis_ready && s_axis_valid;
assign s_axis_write_s = s_axis_ready && s_axis_valid && ~s_axis_full;
always @(posedge s_axis_aclk)
begin
if (!s_axis_aresetn)
Expand All @@ -110,7 +110,7 @@ end
// Read address counter
//------------------------------------------------------------------------------

assign m_axis_read_s = m_axis_ready && m_axis_valid;
assign m_axis_read_s = m_axis_ready && m_axis_valid && ~m_axis_empty;
always @(posedge m_axis_aclk)
begin
if (!m_axis_aresetn)
Expand Down

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