progress on synchronous gpmc, but it may not be possible due to the limited number of clock edges

1 files changed, 26 insertions, 0 deletions

diff --git a/usrp2/gpmc/fifo_watcher.v b/usrp2/gpmc/fifo_watcher.v
new file mode 100644
index 000000000..8b8f1abfb
--- /dev/null
+++ b/usrp2/gpmc/fifo_watcher.v
@@ -0,0 +1,26 @@
+
+
+module fifo_watcher
+  (input clk, input reset, input clear,
+   input src_rdy, input dst_rdy, input sof, input eof,
+   output have_packet, output [15:0] length, input next);
+
+   wire   write = src_rdy & dst_rdy & eof;
+   
+   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), .dst_rdy_i(next) );
+
+   reg [15:0] counter;
+   always @(posedge clk)
+     if(reset | clear)
+       counter <= 1;   // Start at 1
+     else if(src_rdy & dst_rdy)
+       if(eof)
+	 counter <= 1;
+       else
+	 counter <= counter + 1;
+   
+
+endmodule // fifo_watcher