Merge branch 'ue1_rev2' into usrp_e_next

1 files changed, 24 insertions, 20 deletions

diff --git a/fpga/usrp2/fifo/fifo36_to_fifo19.v b/fpga/usrp2/fifo/fifo36_to_fifo19.v
index de249aaeb..517a2a476 100644
--- a/fpga/usrp2/fifo/fifo36_to_fifo19.v
+++ b/fpga/usrp2/fifo/fifo36_to_fifo19.v
@@ -1,33 +1,38 @@
 
-module fifo36_to_fifo19
-  (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 );
+// 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   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 f19_dataout[15:0] = phase ? f36_datain[15:0] : f36_datain[31:16];
+   reg 	  phase;
+   
+   wire   half_line 	   = f36_eof & ((f36_occ==1)|(f36_occ==2));
+   
+   assign f19_dataout[15:0] = (LE ^ phase) ? f36_datain[15:0] : f36_datain[31:16];
    assign f19_dataout[16]  = phase ? 0 : f36_sof;
    assign f19_dataout[17]  = phase ? f36_eof : half_line;
    assign f19_dataout[18]  = f19_dataout[17] & ((f36_occ==1)|(f36_occ==3));
    
    assign f19_src_rdy_o    = f36_src_rdy_i;
    assign f36_dst_rdy_o    = (phase | half_line) & f19_dst_rdy_i;
-	
-   wire f19_xfer 	   = f19_src_rdy_o & f19_dst_rdy_i;
-   wire f36_xfer 	   = f36_src_rdy_i & f36_dst_rdy_o;
-
+   
+   wire   f19_xfer 	   = f19_src_rdy_o & f19_dst_rdy_i;
+   wire   f36_xfer 	   = f36_src_rdy_i & f36_dst_rdy_o;
+   
    always @(posedge clk)
      if(reset)
        phase 		  <= 0;
@@ -36,6 +41,5 @@ module fifo36_to_fifo19
      else if(f19_xfer)
        phase 		  <= 1;
    
-       
+   
 endmodule // fifo36_to_fifo19
-