pluto_hdl_adi/library/common/util_dacfifo_bypass.v

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// ***************************************************************************
// ***************************************************************************
// Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
//
// Each core or library found in this collection may have its own licensing terms.
// The user should keep this in in mind while exploring these cores.
//
// Redistribution and use in source and binary forms,
// with or without modification of this file, are permitted under the terms of either
// (at the option of the user):
//
// 1. The GNU General Public License version 2 as published by the
// Free Software Foundation, which can be found in the top level directory, or at:
// https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
//
// OR
//
// 2. An ADI specific BSD license as noted in the top level directory, or on-line at:
// https://github.com/analogdevicesinc/hdl/blob/dev/LICENSE
//
// ***************************************************************************
// ***************************************************************************
`timescale 1ns/100ps
module util_dacfifo_bypass #(
parameter DAC_DATA_WIDTH = 64,
parameter DMA_DATA_WIDTH = 64) (
// dma fifo interface
input dma_clk,
input [(DMA_DATA_WIDTH-1):0] dma_data,
input dma_ready,
output reg dma_ready_out,
input dma_valid,
// request and syncronizaiton
input dma_xfer_req,
// dac fifo interface
input dac_clk,
input dac_rst,
input dac_valid,
output reg [(DAC_DATA_WIDTH-1):0] dac_data,
output reg dac_dunf
);
// suported ratios: 1:1 / 1:2 / 1:4 / 1:8 / 2:1 / 4:1 / 8:1
localparam MEM_RATIO = (DMA_DATA_WIDTH > DAC_DATA_WIDTH) ? DMA_DATA_WIDTH/DAC_DATA_WIDTH :
DAC_DATA_WIDTH/DMA_DATA_WIDTH;
localparam DAC_ADDRESS_WIDTH = 10;
localparam DMA_ADDRESS_WIDTH = (MEM_RATIO == 1) ? DAC_ADDRESS_WIDTH :
(MEM_RATIO == 2) ? ((DMA_DATA_WIDTH > DAC_DATA_WIDTH) ? (DAC_ADDRESS_WIDTH - 1) : (DAC_ADDRESS_WIDTH + 1)) :
(MEM_RATIO == 4) ? ((DMA_DATA_WIDTH > DAC_DATA_WIDTH) ? (DAC_ADDRESS_WIDTH - 2) : (DAC_ADDRESS_WIDTH + 2)) :
((DMA_DATA_WIDTH > DAC_DATA_WIDTH) ? (DAC_ADDRESS_WIDTH - 3) : (DAC_ADDRESS_WIDTH + 3));
localparam DMA_BUF_THRESHOLD_HI = {(DMA_ADDRESS_WIDTH){1'b1}} - 4;
localparam DAC_BUF_THRESHOLD_LO = 4;
reg [(DMA_ADDRESS_WIDTH-1):0] dma_mem_waddr = 'd0;
reg [(DMA_ADDRESS_WIDTH-1):0] dma_mem_waddr_g = 'd0;
reg [(DAC_ADDRESS_WIDTH-1):0] dac_mem_raddr = 'd0;
reg [(DAC_ADDRESS_WIDTH-1):0] dac_mem_raddr_g = 'd0;
reg dma_rst_m1 = 1'b0;
reg dma_rst = 1'b0;
reg [DMA_ADDRESS_WIDTH-1:0] dma_mem_addr_diff = 1'b0;
reg [(DAC_ADDRESS_WIDTH-1):0] dma_mem_raddr_m1 = 1'b0;
reg [(DAC_ADDRESS_WIDTH-1):0] dma_mem_raddr_m2 = 1'b0;
reg [(DAC_ADDRESS_WIDTH-1):0] dma_mem_raddr = 1'b0;
reg [DAC_ADDRESS_WIDTH-1:0] dac_mem_addr_diff = 1'b0;
reg [(DMA_ADDRESS_WIDTH-1):0] dac_mem_waddr_m1 = 1'b0;
reg [(DMA_ADDRESS_WIDTH-1):0] dac_mem_waddr_m2 = 1'b0;
reg [(DMA_ADDRESS_WIDTH-1):0] dac_mem_waddr = 1'b0;
reg dac_mem_ready = 1'b0;
reg dac_xfer_out = 1'b0;
reg dac_xfer_out_m1 = 1'b0;
// internal signals
wire dma_mem_last_read_s;
wire [(DMA_ADDRESS_WIDTH):0] dma_mem_addr_diff_s;
wire [(DAC_ADDRESS_WIDTH):0] dac_mem_addr_diff_s;
wire [(DMA_ADDRESS_WIDTH-1):0] dma_mem_raddr_s;
wire [(DAC_ADDRESS_WIDTH-1):0] dac_mem_waddr_s;
wire dma_mem_wea_s;
wire dac_mem_rea_s;
wire [(DAC_DATA_WIDTH-1):0] dac_mem_rdata_s;
wire [DMA_ADDRESS_WIDTH:0] dma_address_diff_s;
wire [DAC_ADDRESS_WIDTH:0] dac_address_diff_s;
// binary to grey conversion
function [7:0] b2g;
input [7:0] b;
reg [7:0] g;
begin
g[7] = b[7];
g[6] = b[7] ^ b[6];
g[5] = b[6] ^ b[5];
g[4] = b[5] ^ b[4];
g[3] = b[4] ^ b[3];
g[2] = b[3] ^ b[2];
g[1] = b[2] ^ b[1];
g[0] = b[1] ^ b[0];
b2g = g;
end
endfunction
// grey to binary conversion
function [7:0] g2b;
input [7:0] g;
reg [7:0] b;
begin
b[7] = g[7];
b[6] = b[7] ^ g[6];
b[5] = b[6] ^ g[5];
b[4] = b[5] ^ g[4];
b[3] = b[4] ^ g[3];
b[2] = b[3] ^ g[2];
b[1] = b[2] ^ g[1];
b[0] = b[1] ^ g[0];
g2b = b;
end
endfunction
// An asymmetric memory to transfer data from DMAC interface to DAC interface
ad_mem_asym #(
.A_ADDRESS_WIDTH (DMA_ADDRESS_WIDTH),
.A_DATA_WIDTH (DMA_DATA_WIDTH),
.B_ADDRESS_WIDTH (DAC_ADDRESS_WIDTH),
.B_DATA_WIDTH (DAC_DATA_WIDTH))
i_mem_asym (
.clka (dma_clk),
.wea (dma_mem_wea_s),
.addra (dma_mem_waddr),
.dina (dma_data),
.clkb (dac_clk),
.addrb (dac_mem_raddr),
.doutb (dac_mem_rdata_s));
// dma reset is brought from dac domain
always @(posedge dma_clk) begin
dma_rst_m1 <= dac_rst;
dma_rst <= dma_rst_m1;
end
// Write address generation for the asymmetric memory
assign dma_mem_wea_s = dma_xfer_req & dma_valid & dma_ready;
always @(posedge dma_clk) begin
if (dma_rst == 1'b1) begin
dma_mem_waddr <= 'h0;
dma_mem_waddr_g <= 'h0;
end else begin
if (dma_mem_wea_s == 1'b1) begin
dma_mem_waddr <= dma_mem_waddr + 1;
end
dma_mem_waddr_g <= b2g(dma_mem_waddr);
end
end
// The memory module request data until reaches the high threshold.
always @(posedge dma_clk) begin
if (dma_rst == 1'b1) begin
dma_mem_addr_diff <= 'b0;
dma_mem_raddr_m1 <= 'b0;
dma_mem_raddr_m2 <= 'b0;
dma_mem_raddr <= 'b0;
dma_ready_out <= 1'b0;
end else begin
dma_mem_raddr_m1 <= dac_mem_raddr_g;
dma_mem_raddr_m2 <= dma_mem_raddr_m1;
dma_mem_raddr <= g2b(dma_mem_raddr_m2);
dma_mem_addr_diff <= dma_address_diff_s[DMA_ADDRESS_WIDTH-1:0];
if (dma_mem_addr_diff >= DMA_BUF_THRESHOLD_HI) begin
dma_ready_out <= 1'b0;
end else begin
dma_ready_out <= 1'b1;
end
end
end
// relative address offset on dma domain
assign dma_address_diff_s = {1'b1, dma_mem_waddr} - dma_mem_raddr_s;
assign dma_mem_raddr_s = (DMA_DATA_WIDTH>DAC_DATA_WIDTH) ?
((MEM_RATIO == 1) ? (dma_mem_raddr) :
(MEM_RATIO == 2) ? (dma_mem_raddr[(DAC_ADDRESS_WIDTH-1):1]) :
(MEM_RATIO == 4) ? (dma_mem_raddr[(DAC_ADDRESS_WIDTH-1):2]) : (dma_mem_raddr[(DAC_ADDRESS_WIDTH-1):3])) :
((MEM_RATIO == 1) ? (dma_mem_raddr) :
(MEM_RATIO == 2) ? ({dma_mem_raddr, 1'b0}) :
(MEM_RATIO == 4) ? ({dma_mem_raddr, 2'b0}) : ({dma_mem_raddr, 3'b0}));
// relative address offset on dac domain
assign dac_address_diff_s = {1'b1, dac_mem_raddr} - dac_mem_waddr_s;
assign dac_mem_waddr_s = (DAC_DATA_WIDTH>DMA_DATA_WIDTH) ?
((MEM_RATIO == 1) ? (dac_mem_waddr) :
(MEM_RATIO == 2) ? (dac_mem_waddr[(DMA_ADDRESS_WIDTH-1):1]) :
(MEM_RATIO == 4) ? (dac_mem_waddr[(DMA_ADDRESS_WIDTH-1):2]) : (dac_mem_waddr[(DMA_ADDRESS_WIDTH-1):3])) :
((MEM_RATIO == 1) ? (dac_mem_waddr) :
(MEM_RATIO == 2) ? ({dac_mem_waddr, 1'b0}) :
(MEM_RATIO == 4) ? ({dac_mem_waddr, 2'b0}) : ({dac_mem_waddr, 3'b0}));
// Read address generation for the asymmetric memory
assign dac_mem_rea_s = dac_valid & dac_mem_ready;
always @(posedge dac_clk) begin
if (dac_rst == 1'b1) begin
dac_mem_raddr <= 'h0;
dac_mem_raddr_g <= 'h0;
end else begin
if (dac_mem_rea_s == 1'b1) begin
dac_mem_raddr <= dac_mem_raddr + 1;
end
dac_mem_raddr_g <= b2g(dac_mem_raddr);
end
end
// The memory module is ready if it's not empty
always @(posedge dac_clk) begin
if (dac_rst == 1'b1) begin
dac_mem_addr_diff <= 'b0;
dac_mem_waddr_m1 <= 'b0;
dac_mem_waddr_m2 <= 'b0;
dac_mem_waddr <= 'b0;
dac_mem_ready <= 1'b0;
end else begin
dac_mem_waddr_m1 <= dma_mem_waddr_g;
dac_mem_waddr_m2 <= dac_mem_waddr_m1;
dac_mem_waddr <= g2b(dac_mem_waddr_m2);
dac_mem_addr_diff <= dac_address_diff_s[DAC_ADDRESS_WIDTH-1:0];
if (dac_mem_addr_diff > 0) begin
dac_mem_ready <= 1'b1;
end else begin
dac_mem_ready <= 1'b0;
end
end
end
// define underflow
always @(posedge dac_clk) begin
if (dac_rst == 1'b1) begin
dac_xfer_out_m1 <= 1'b0;
dac_xfer_out <= 1'b0;
dac_dunf <= 1'b0;
end else begin
dac_xfer_out_m1 <= dma_xfer_req;
dac_xfer_out <= dac_xfer_out_m1;
dac_dunf <= (dac_valid == 1'b1) ? (dac_xfer_out & ~dac_mem_ready) : dac_dunf;
end
end
// DAC data output logic
always @(posedge dac_clk) begin
if (dac_rst == 1'b1) begin
dac_data <= 0;
end else begin
dac_data <= dac_mem_rdata_s;
end
end
endmodule