u1p: pass tx status/error packets back through GPIF over the response channel (short packets)

3 files changed, 80 insertions, 1 deletions

diff --git a/usrp2/fifo/Makefile.srcs b/usrp2/fifo/Makefile.srcs
index 7e6a231ae..02c567049 100644
--- a/usrp2/fifo/Makefile.srcs
+++ b/usrp2/fifo/Makefile.srcs
@@ -23,6 +23,7 @@ fifo19_to_ll8.v \
 ll8_to_fifo19.v \
 fifo36_to_fifo19.v \
 fifo19_to_fifo36.v \
+fifo19_mux.v \
 fifo36_mux.v \
 fifo36_demux.v \
 packet_router.v \
diff --git a/usrp2/fifo/fifo19_mux.v b/usrp2/fifo/fifo19_mux.v
new file mode 100644
index 000000000..ebf961678
--- /dev/null
+++ b/usrp2/fifo/fifo19_mux.v
@@ -0,0 +1,77 @@
+
+// Mux packets from multiple FIFO interfaces onto a single one.
+//  Can alternate or give priority to one port (port 0)
+//  In prio mode, port 1 will never get access if port 0 is always busy
+
+module fifo19_mux
+  #(parameter prio = 0)
+   (input clk, input reset, input clear,
+    input [18:0] data0_i, input src0_rdy_i, output dst0_rdy_o,
+    input [18:0] data1_i, input src1_rdy_i, output dst1_rdy_o,
+    output [18:0] data_o, output src_rdy_o, input dst_rdy_i);
+
+   wire [18:0] 	  data0_int, data1_int;
+   wire 	  src0_rdy_int, dst0_rdy_int, src1_rdy_int, dst1_rdy_int;
+   
+   fifo_short #(.WIDTH(19)) mux_fifo_in0
+     (.clk(clk), .reset(reset), .clear(clear),
+      .datain(data0_i), .src_rdy_i(src0_rdy_i), .dst_rdy_o(dst0_rdy_o),
+      .dataout(data0_int), .src_rdy_o(src0_rdy_int), .dst_rdy_i(dst0_rdy_int));
+
+   fifo_short #(.WIDTH(19)) mux_fifo_in1
+     (.clk(clk), .reset(reset), .clear(clear),
+      .datain(data1_i), .src_rdy_i(src1_rdy_i), .dst_rdy_o(dst1_rdy_o),
+      .dataout(data1_int), .src_rdy_o(src1_rdy_int), .dst_rdy_i(dst1_rdy_int));
+
+   localparam MUX_IDLE0 = 0;
+   localparam MUX_DATA0 = 1;
+   localparam MUX_IDLE1 = 2;
+   localparam MUX_DATA1 = 3;
+   
+   reg [1:0] 	  state;
+
+   wire 	  eof0 = data0_int[17];
+   wire 	  eof1 = data1_int[17];
+   
+   wire [18:0] 	  data_int;
+   wire 	  src_rdy_int, dst_rdy_int;
+   
+   always @(posedge clk)
+     if(reset | clear)
+       state <= MUX_IDLE0;
+     else
+       case(state)
+	 MUX_IDLE0 :
+	   if(src0_rdy_int)
+	     state <= MUX_DATA0;
+	   else if(src1_rdy_int)
+	     state <= MUX_DATA1;
+
+	 MUX_DATA0 :
+	   if(src0_rdy_int & dst_rdy_int & eof0)
+	     state <= prio ? MUX_IDLE0 : MUX_IDLE1;
+
+	 MUX_IDLE1 :
+	   if(src1_rdy_int)
+	     state <= MUX_DATA1;
+	   else if(src0_rdy_int)
+	     state <= MUX_DATA0;
+	   
+	 MUX_DATA1 :
+	   if(src1_rdy_int & dst_rdy_int & eof1)
+	     state <= MUX_IDLE0;
+	 
+	 default :
+	   state <= MUX_IDLE0;
+       endcase // case (state)
+
+   assign dst0_rdy_int = (state==MUX_DATA0) ? dst_rdy_int : 0;
+   assign dst1_rdy_int = (state==MUX_DATA1) ? dst_rdy_int : 0;
+   assign src_rdy_int = (state==MUX_DATA0) ? src0_rdy_int : (state==MUX_DATA1) ? src1_rdy_int : 0;
+   assign data_int = (state==MUX_DATA0) ? data0_int : data1_int;
+   
+   fifo_short #(.WIDTH(19)) mux_fifo
+     (.clk(clk), .reset(reset), .clear(clear),
+      .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int),
+      .dataout(data_o), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i));
+endmodule // fifo19_mux
diff --git a/usrp2/fifo/fifo36_mux.v b/usrp2/fifo/fifo36_mux.v
index 7f0f803ff..2b454abaf 100644
--- a/usrp2/fifo/fifo36_mux.v
+++ b/usrp2/fifo/fifo36_mux.v
@@ -74,4 +74,5 @@ module fifo36_mux
      (.clk(clk), .reset(reset), .clear(clear),
       .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int),
       .dataout(data_o), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i));
-endmodule // fifo36_demux
+
+endmodule // fifo36_mux