pluto_hdl_adi/library/common/ad_xcvr_rx_if.v

101 lines
3.4 KiB
Verilog

// ***************************************************************************
// ***************************************************************************
// Copyright (C) 2016-2023 Analog Devices, Inc. All rights reserved.
//
// In this HDL repository, there are many different and unique modules, consisting
// of various HDL (Verilog or VHDL) components. The individual modules are
// developed independently, and may be accompanied by separate and unique license
// terms.
//
// The user should read each of these license terms, and understand the
// freedoms and responsibilities that he or she has by using this source/core.
//
// This core is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
// A PARTICULAR PURPOSE.
//
// Redistribution and use of source or resulting binaries, with or without modification
// of this file, are permitted under one of the following two license terms:
//
// 1. The GNU General Public License version 2 as published by the
// Free Software Foundation, which can be found in the top level directory
// of this repository (LICENSE_GPL2), and also online at:
// <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
//
// OR
//
// 2. An ADI specific BSD license, which can be found in the top level directory
// of this repository (LICENSE_ADIBSD), and also on-line at:
// https://github.com/analogdevicesinc/hdl/blob/master/LICENSE_ADIBSD
// This will allow to generate bit files and not release the source code,
// as long as it attaches to an ADI device.
//
// ***************************************************************************
// ***************************************************************************
`timescale 1ns/100ps
module ad_xcvr_rx_if #(
parameter OCTETS_PER_BEAT = 4,
parameter DW = OCTETS_PER_BEAT * 8
) (
// jesd interface
input rx_clk,
input [OCTETS_PER_BEAT-1:0] rx_ip_sof,
input [DW-1:0] rx_ip_data,
output reg rx_sof,
output reg [DW-1:0] rx_data
);
// rx_ip_sof:
// The input beat may contain more than one frame per clock, a sof bit is set for
// each frame.
// Every bit that corresponds to a octet that is at the beginning of a frame
// the bit is set. E.g for OCTETS_PER_BEAT = 4
// if F=1 all bits are set,
// F=2 sof=4'b0101,
// F=4 sof=4'b0001
//
// rx_ip_data:
// The temporal ordering of the octets is from LSB to MSB,
// this means the octet placed in the lowest 8 bits was received first,
// the octet placed in the highest 8 bits was received last.
// internal registers
reg [DW-1:0] rx_ip_data_d = 'd0;
reg [OCTETS_PER_BEAT-1:0] rx_ip_sof_hold = 'd0;
reg [OCTETS_PER_BEAT-1:0] rx_ip_sof_d = 'd0;
always @(posedge rx_clk) begin
rx_ip_data_d <= rx_ip_data;
rx_ip_sof_d <= rx_ip_sof;
if (|rx_ip_sof) begin
rx_ip_sof_hold <= rx_ip_sof;
end
rx_sof <= |rx_ip_sof_d;
end
wire [OCTETS_PER_BEAT*DW-1:0] rx_data_s;
assign rx_data_s[0 +: DW] = rx_ip_data;
generate
genvar i;
for (i = 1; i < OCTETS_PER_BEAT; i = i + 1) begin : g_rx_data_opt
assign rx_data_s[i*DW +: DW] = {rx_ip_data[i*8-1 : 0], rx_ip_data_d[DW-1 : i*8]};
end
endgenerate
integer j;
always @(posedge rx_clk) begin
for (j = OCTETS_PER_BEAT-1; j >= 0; j = j - 1) begin
if (rx_ip_sof_hold[j] == 1'b1) begin
rx_data <= rx_data_s[j*DW +: DW];
end
end
end
endmodule