u1p: better way of reframing the packets

1 files changed, 62 insertions, 0 deletions

diff --git a/usrp2/gpif/packet_reframer.v b/usrp2/gpif/packet_reframer.v
new file mode 100644
index 000000000..336c36369
--- /dev/null
+++ b/usrp2/gpif/packet_reframer.v
@@ -0,0 +1,62 @@
+
+// Join vita packets longer than one GPIF frame, drop padding on short frames
+
+module packet_reframer
+  (input clk, input reset, input clear,
+   input [18:0] data_i,
+   input src_rdy_i,
+   output dst_rdy_o,
+   output [18:0] data_o,
+   output src_rdy_o,
+   input dst_rdy_i);
+
+   reg [1:0] state;
+   reg [15:0] length;
+   
+   localparam RF_IDLE = 0;
+   localparam RF_PKT = 1;
+   localparam RF_DUMP = 2;
+   
+   always @(posedge clk)
+     if(reset | clear)
+       state <= 0;
+     else
+       if(src_rdy_i & dst_rdy_i)
+	 case(state)
+	   RF_IDLE :
+	     begin
+		length <= {data_i[14:0],1'b0};
+		state <= RF_PKT;
+	     end
+	   RF_PKT :
+	     begin
+		if(length == 2)
+		  if(data_i[17])
+		    state <= RF_IDLE;
+		  else
+		    state <= RF_DUMP;
+		else
+		  length <= length - 1;
+	     end
+	   RF_DUMP :
+	     if(data_i[17])
+	       state <= RF_IDLE;
+	   default :
+	     state<= RF_IDLE;
+	 endcase // case (state)
+   
+   assign dst_rdy_o = dst_rdy_i; // this is a little pessimistic but ok
+   assign src_rdy_o = src_rdy_i & (state != RF_DUMP);
+   
+   wire occ_out = 0;
+   wire eof_out = (state == RF_PKT) & (length == 2);
+   wire sof_out = (state == RF_IDLE);
+   wire [15:0] data_out = data_i[15:0];
+   assign data_o = {occ_out, eof_out, sof_out, data_out};
+   
+      
+endmodule // packet_reframer
+
+
+
+