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//
// Copyright 2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
module fifo19_to_ll8
(input clk, input reset, input clear,
input [18:0] f19_data,
input f19_src_rdy_i,
output f19_dst_rdy_o,
output reg [7:0] ll_data,
output ll_sof_n,
output ll_eof_n,
output ll_src_rdy_n,
input ll_dst_rdy_n);
wire ll_sof, ll_eof, ll_src_rdy;
assign ll_sof_n = ~ll_sof;
assign ll_eof_n = ~ll_eof;
assign ll_src_rdy_n = ~ll_src_rdy;
wire ll_dst_rdy = ~ll_dst_rdy_n;
wire f19_sof = f19_data[16];
wire f19_eof = f19_data[17];
wire f19_occ = f19_data[18];
wire advance, end_early;
reg state;
always @(posedge clk)
if(reset)
state <= 0;
else
if(advance)
if(ll_eof)
state <= 0;
else
state <= state + 1;
always @*
case(state)
0 : ll_data = f19_data[15:8];
1 : ll_data = f19_data[7:0];
default : ll_data = f19_data[15:8];
endcase // case (state)
assign ll_sof = (state==0) & f19_sof;
assign ll_eof = f19_eof & ((f19_occ==1)|(state==1));
assign ll_src_rdy = f19_src_rdy_i;
assign advance = ll_src_rdy & ll_dst_rdy;
assign f19_dst_rdy_o = advance & ((state==1)|ll_eof);
endmodule // fifo19_to_ll8
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