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diff --git a/fpga/usrp2/fifo/fifo36_to_fifo19.v b/fpga/usrp2/fifo/fifo36_to_fifo19.v
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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/>.
+//
+
+
+// Parameter LE tells us if we are little-endian.
+// Little-endian means send lower 16 bits first.
+// Default is big endian (network order), send upper bits first.
+
+module fifo36_to_fifo19
+ #(parameter LE=0)
+ (input clk, input reset, input clear,
+ input [35:0] f36_datain,
+ input f36_src_rdy_i,
+ output f36_dst_rdy_o,
+
+ output [18:0] f19_dataout,
+ output f19_src_rdy_o,
+ input f19_dst_rdy_i );
+
+ wire [18:0] f19_data_int;
+ wire f19_src_rdy_int, f19_dst_rdy_int;
+ wire [35:0] f36_data_int;
+ wire f36_src_rdy_int, f36_dst_rdy_int;
+
+ // Shortfifo on input to guarantee no deadlock
+ fifo_short #(.WIDTH(36)) head_fifo
+ (.clk(clk),.reset(reset),.clear(clear),
+ .datain(f36_datain), .src_rdy_i(f36_src_rdy_i), .dst_rdy_o(f36_dst_rdy_o),
+ .dataout(f36_data_int), .src_rdy_o(f36_src_rdy_int), .dst_rdy_i(f36_dst_rdy_int),
+ .space(),.occupied() );
+
+ // Main fifo36_to_fifo19, needs shortfifos to guarantee no deadlock
+ wire [1:0] f36_occ_int = f36_data_int[35:34];
+ wire f36_sof_int = f36_data_int[32];
+ wire f36_eof_int = f36_data_int[33];
+
+ reg phase;
+ wire half_line = f36_eof_int & ((f36_occ_int==1)|(f36_occ_int==2));
+
+ assign f19_data_int[15:0] = (LE ^ phase) ? f36_data_int[15:0] : f36_data_int[31:16];
+ assign f19_data_int[16] = phase ? 0 : f36_sof_int;
+ assign f19_data_int[17] = phase ? f36_eof_int : half_line;
+ assign f19_data_int[18] = f19_data_int[17] & ((f36_occ_int==1)|(f36_occ_int==3));
+
+ assign f19_src_rdy_int = f36_src_rdy_int;
+ assign f36_dst_rdy_int = (phase | half_line) & f19_dst_rdy_int;
+
+ wire f19_xfer = f19_src_rdy_int & f19_dst_rdy_int;
+ wire f36_xfer = f36_src_rdy_int & f36_dst_rdy_int;
+
+ always @(posedge clk)
+ if(reset)
+ phase <= 0;
+ else if(f36_xfer)
+ phase <= 0;
+ else if(f19_xfer)
+ phase <= 1;
+
+ // Shortfifo on output to guarantee no deadlock
+ fifo_short #(.WIDTH(19)) tail_fifo
+ (.clk(clk),.reset(reset),.clear(clear),
+ .datain(f19_data_int), .src_rdy_i(f19_src_rdy_int), .dst_rdy_o(f19_dst_rdy_int),
+ .dataout(f19_dataout), .src_rdy_o(f19_src_rdy_o), .dst_rdy_i(f19_dst_rdy_i),
+ .space(),.occupied() );
+
+endmodule // fifo36_to_fifo19