1 files changed, 54 insertions, 0 deletions
diff --git a/fpga/usrp2/simple_gemac/rxmac_to_ll8.v b/fpga/usrp2/simple_gemac/rxmac_to_ll8.v
new file mode 100644
index 000000000..5ec233d95
--- /dev/null
+++ b/fpga/usrp2/simple_gemac/rxmac_to_ll8.v
@@ -0,0 +1,54 @@
+
+module rxmac_to_ll8
+  (input clk, input reset, input clear,
+   input [7:0] rx_data, input rx_valid, input rx_error, input rx_ack,
+   output [7:0] ll_data, output ll_sof, output ll_eof, output ll_error, output ll_src_rdy, input ll_dst_rdy );
+
+   reg [2:0] xfer_state;
+
+   localparam XFER_IDLE     = 0;
+   localparam XFER_ACTIVE   = 1;
+   localparam XFER_ERROR    = 2;
+   localparam XFER_ERROR2   = 3;
+   localparam XFER_OVERRUN  = 4;
+   localparam XFER_OVERRUN2 = 5;
+      
+   assign ll_data 	    = rx_data;
+   assign ll_src_rdy 	    = ((rx_valid & (xfer_state != XFER_OVERRUN2) )
+			       | (xfer_state == XFER_ERROR) 
+			       | (xfer_state == XFER_OVERRUN));
+   assign ll_sof 	    = ((xfer_state==XFER_IDLE)|(xfer_state==XFER_ERROR)|(xfer_state==XFER_OVERRUN));
+   assign ll_eof 	    = (rx_ack | (xfer_state==XFER_ERROR) | (xfer_state==XFER_OVERRUN));
+   assign ll_error 	    = (xfer_state == XFER_ERROR)|(xfer_state==XFER_OVERRUN);
+   
+   always @(posedge clk)
+     if(reset | clear)
+       xfer_state 	   <= XFER_IDLE;
+     else
+       case(xfer_state)
+	 XFER_IDLE :
+	   if(rx_valid)
+	     xfer_state <= XFER_ACTIVE;
+	 XFER_ACTIVE :
+	   if(rx_error)
+	     xfer_state <= XFER_ERROR;
+	   else if(~rx_valid)
+	     xfer_state <= XFER_IDLE;
+	   else if(~ll_dst_rdy)
+	     xfer_state <= XFER_OVERRUN;
+	 XFER_ERROR :
+	   if(ll_dst_rdy)
+	     xfer_state <= XFER_ERROR2;
+	 XFER_ERROR2 :
+	   if(~rx_error)
+	     xfer_state <= XFER_IDLE;
+	 XFER_OVERRUN :
+	   if(ll_dst_rdy)
+	     xfer_state <= XFER_OVERRUN2;
+	 XFER_OVERRUN2 :
+	   if(~rx_valid)
+	     xfer_state <= XFER_IDLE;
+       endcase // case (xfer_state)
+
+   
+endmodule // rxmac_to_ll8