Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus.

1 files changed, 31 insertions, 0 deletions

diff --git a/fpga/usrp3/lib/fifo/axi_fifo64_to_fifo32.v b/fpga/usrp3/lib/fifo/axi_fifo64_to_fifo32.v
new file mode 100644
index 000000000..46b021600
--- /dev/null
+++ b/fpga/usrp3/lib/fifo/axi_fifo64_to_fifo32.v
@@ -0,0 +1,31 @@
+
+module axi_fifo64_to_fifo32
+  (input clk, input reset, input clear,
+   input [63:0] i_tdata, input [2:0] i_tuser, input i_tlast, input i_tvalid, output i_tready,
+   output [31:0] o_tdata, output [1:0] o_tuser, output o_tlast, output o_tvalid, input o_tready
+   );
+
+   wire 	 short_last = i_tlast & ((i_tuser == 3'd1) | (i_tuser == 3'd2) | (i_tuser == 3'd3) | (i_tuser == 3'd4));
+   
+   reg 		 state;
+   always @(posedge clk)
+     if(reset | clear)
+       state <= 1'b0;
+     else
+       if(i_tvalid & o_tready)
+	 case(state)
+	   1'b0 :
+	     if(~short_last)
+	       state <= 1'b1;
+	   1'b1 :
+	     state <= 1'b0;
+	 endcase // case (state)
+   
+   assign o_tdata = (state == 0) ? i_tdata[63:32] : i_tdata[31:0];
+   assign o_tuser = o_tlast ? i_tuser[1:0] : 2'd0;
+   assign o_tlast = i_tlast & ((state == 1'b1) | short_last);
+
+   assign o_tvalid = i_tvalid;
+   assign i_tready = o_tready & ((state == 1'b1) | short_last);
+   		    
+endmodule // axi_fifo64_to_fifo32