pluto_hdl_adi/library/jesd204/jesd204_rx/elastic_buffer.v

143 lines
3.2 KiB
Verilog

// ***************************************************************************
// ***************************************************************************
// Copyright (C) 2017, 2018, 2021, 2022 Analog Devices, Inc. All rights reserved.
// SPDX short identifier: ADIJESD204
// ***************************************************************************
// ***************************************************************************
`timescale 1ns/100ps
module elastic_buffer #(
parameter IWIDTH = 32,
parameter OWIDTH = 48,
parameter SIZE = 256,
parameter ASYNC_CLK = 0
) (
input clk,
input reset,
input device_clk,
input device_reset,
input [IWIDTH-1:0] wr_data,
output [OWIDTH-1:0] rd_data,
input ready_n,
input do_release_n
);
localparam ADDR_WIDTH = SIZE > 128 ? 7 :
SIZE > 64 ? 6 :
SIZE > 32 ? 5 :
SIZE > 16 ? 4 :
SIZE > 8 ? 3 :
SIZE > 4 ? 2 :
SIZE > 2 ? 1 : 0;
localparam WIDTH = OWIDTH >= IWIDTH ? OWIDTH : IWIDTH;
reg [ADDR_WIDTH:0] wr_addr = 'h00;
reg [ADDR_WIDTH:0] rd_addr = 'h00;
(* ram_style = "distributed" *) reg [WIDTH-1:0] mem[0:SIZE - 1];
reg mem_rd_valid = 'b0;
reg [WIDTH-1:0] mem_rd_data;
wire mem_wr;
wire [WIDTH-1:0] mem_wr_data;
wire unpacker_ready;
generate if ((OWIDTH < IWIDTH) && ASYNC_CLK) begin
assign mem_wr = 1'b1;
always @(posedge clk) begin
if (ready_n) begin
wr_addr <= 'h00;
end else if (mem_wr) begin
wr_addr <= wr_addr + 1;
end
end
always @(posedge clk) begin
if (mem_wr) begin
mem[wr_addr] <= wr_data;
end
end
assign mem_rd_en = ~do_release_n & unpacker_ready;
always @(posedge device_clk) begin
if (mem_rd_en) begin
mem_rd_data <= mem[rd_addr];
end
mem_rd_valid <= mem_rd_en;
end
always @(posedge device_clk) begin
if (do_release_n) begin
rd_addr <= 'b0;
end else if (mem_rd_en) begin
rd_addr <= rd_addr + 1;
end
end
ad_upack #(
.I_W(IWIDTH/8),
.O_W(OWIDTH/8),
.UNIT_W(8),
.O_REG(0)
) i_ad_upack (
.clk(device_clk),
.reset(do_release_n),
.idata(mem_rd_data),
.ivalid(mem_rd_valid),
.iready(unpacker_ready),
.odata(rd_data),
.ovalid());
end else begin
if ((OWIDTH > IWIDTH) && ASYNC_CLK) begin
ad_pack #(
.I_W(IWIDTH/8),
.O_W(OWIDTH/8),
.UNIT_W(8)
) i_ad_pack (
.clk(clk),
.reset(ready_n),
.idata(wr_data),
.ivalid(1'b1),
.odata(mem_wr_data),
.ovalid(mem_wr));
end else begin
assign mem_wr = 1'b1;
assign mem_wr_data = wr_data;
end
always @(posedge clk) begin
if (ready_n == 1'b1) begin
wr_addr <= 'h00;
end else if (mem_wr) begin
mem[wr_addr] <= mem_wr_data;
wr_addr <= wr_addr + 1'b1;
end
end
always @(posedge device_clk) begin
if (do_release_n == 1'b1) begin
rd_addr <= 'h00;
end else begin
rd_addr <= rd_addr + 1'b1;
mem_rd_data <= mem[rd_addr];
end
end
assign rd_data = mem_rd_data;
end
endgenerate
endmodule