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//
// Copyright 2013 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: LGPL-3.0-or-later
//
//
//
// Provide required handshake to Opencores XGE MAC to initiate Rx of one available packet
//
//
module xge_handshake
(
input clk,
input reset,
output reg pkt_rx_ren,
input pkt_rx_avail,
input pkt_rx_eop
);
localparam IDLE=0;
localparam RX=1;
reg state;
always @(posedge clk)
if (reset) begin
pkt_rx_ren <= 0;
state <= IDLE;
end else begin
case (state)
//
// Wait for pkt_rx_avail to be asserted, then assert pkt_rx_ren next cycle
//
IDLE: begin
if (pkt_rx_avail) begin
pkt_rx_ren <= 1;
state <= RX;
end else begin
pkt_rx_ren <= 0;
state <= IDLE;
end
end
//
// Keep pkt_rx_ren asserted until EOF received.
//
RX: begin
if (pkt_rx_eop) begin
pkt_rx_ren <= 0;
state <= IDLE;
end else begin
pkt_rx_ren <= 1;
state <= RX;
end
end
endcase // case(state)
end // else: !if(reset)
endmodule // xge_handshake
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