1 files changed, 42 insertions, 0 deletions
diff --git a/simple_gemac/rxmac_to_ll8.v b/simple_gemac/rxmac_to_ll8.v
new file mode 100644
index 000000000..9a795b257
--- /dev/null
+++ b/simple_gemac/rxmac_to_ll8.v
@@ -0,0 +1,42 @@
+
+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_src_rdy, input ll_dst_rdy );
+
+   assign ll_data 	= rx_data;
+   assign ll_src_rdy 	= rx_valid;
+   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));
+   
+   reg [1:0] xfer_state;
+   localparam XFER_IDLE     = 0;
+   localparam XFER_ACTIVE   = 1;
+   localparam XFER_ERROR    = 2;
+   localparam XFER_OVERRUN  = 3;
+   
+   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(~rx_valid)
+	     xfer_state <= XFER_IDLE;
+	 XFER_OVERRUN :
+	   if(ll_dst_rdy & ~rx_valid)
+	     xfer_state <= XFER_IDLE;
+       endcase // case (xfer_state)
+
+   
+endmodule // rxmac_to_ll8