Merge branch 'uhd_fpga_merge' into pre_merge

1 files changed, 40 insertions, 0 deletions

diff --git a/fpga/usrp2/fifo/fifo36_to_fifo18.v b/fpga/usrp2/fifo/fifo36_to_fifo18.v
new file mode 100644
index 000000000..b636ab9ca
--- /dev/null
+++ b/fpga/usrp2/fifo/fifo36_to_fifo18.v
@@ -0,0 +1,40 @@
+
+module fifo36_to_fifo18
+  (input clk, input reset, input clear,
+   input [35:0] f36_datain,
+   input f36_src_rdy_i,
+   output f36_dst_rdy_o,
+   
+   output [17:0] f18_dataout,
+   output f18_src_rdy_o,
+   input f18_dst_rdy_i );
+
+   wire   f36_sof  = f36_datain[32];
+   wire   f36_eof  = f36_datain[33];
+   wire   f36_occ  = f36_datain[35:34];
+
+   reg phase;
+
+   wire half_line 	   = f36_eof & ((f36_occ==1)|(f36_occ==2));
+   
+   assign f18_dataout[15:0] = phase ? f36_datain[15:0] : f36_datain[31:16];
+   assign f18_dataout[16]  = phase ? 0 : f36_sof;
+   assign f18_dataout[17]  = phase ? f36_eof : half_line;
+   
+   assign f18_src_rdy_o    = f36_src_rdy_i;
+   assign f36_dst_rdy_o    = (phase | half_line) & f18_dst_rdy_i;
+	
+   wire f18_xfer 	   = f18_src_rdy_o & f18_dst_rdy_i;
+   wire f36_xfer 	   = f36_src_rdy_i & f36_dst_rdy_o;
+
+   always @(posedge clk)
+     if(reset)
+       phase 		  <= 0;
+     else if(f36_xfer)
+       phase 		  <= 0;
+     else if(f18_xfer)
+       phase 		  <= 1;
+   
+       
+endmodule // fifo36_to_fifo18
+