Merge remote branch 'origin/usrp_e_next' into usrp_e_next

1 files changed, 56 insertions, 0 deletions

diff --git a/fpga/usrp2/gpmc/fifo_watcher.v b/fpga/usrp2/gpmc/fifo_watcher.v
new file mode 100644
index 000000000..fe4e35de3
--- /dev/null
+++ b/fpga/usrp2/gpmc/fifo_watcher.v
@@ -0,0 +1,56 @@
+
+
+module fifo_watcher
+  (input clk, input reset, input clear,
+   input src_rdy1, input dst_rdy1, input sof1, input eof1,
+   input src_rdy2, input dst_rdy2, input sof2, input eof2,
+   output reg have_packet, output [15:0] length, output reg bus_error,
+   output [31:0] debug);
+
+   wire   write = src_rdy1 & dst_rdy1 & eof1;
+   wire   read = src_rdy2 & dst_rdy2 & eof2;
+   wire   have_packet_int;
+   reg [15:0] counter;
+   wire [4:0] pkt_count;
+   assign debug = pkt_count;
+   
+   fifo_short #(.WIDTH(16)) frame_lengths
+     (.clk(clk), .reset(reset), .clear(clear),
+      .datain(counter), .src_rdy_i(write), .dst_rdy_o(),
+      .dataout(length), .src_rdy_o(have_packet_int), .dst_rdy_i(read),
+      .occupied(pkt_count), .space());
+
+   always @(posedge clk)
+     if(reset | clear)
+       counter <= 1;   // Start at 1
+     else if(src_rdy1 & dst_rdy1)
+       if(eof1)
+	 counter <= 1;
+       else
+	 counter <= counter + 1;
+
+   always @(posedge clk)
+     if(reset | clear)
+       bus_error <= 0;
+     else if(dst_rdy2 & ~src_rdy2)
+       bus_error <= 1;
+     else if(read & ~have_packet_int)
+       bus_error <= 1;
+
+   reg 	      in_packet;
+   always @(posedge clk)
+     if(reset | clear)
+       have_packet <= 0;
+     else 
+       have_packet <= (have_packet_int & ~in_packet) | (pkt_count>1) ;
+   
+   always @(posedge clk)
+     if(reset | clear)
+       in_packet <= 0;
+     else if(src_rdy2 & dst_rdy2)
+       if(eof2)
+	 in_packet <= 0;
+       else
+	 in_packet <= 1;
+   
+endmodule // fifo_watcher