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-rw-r--r--fpga/usrp2/serdes/serdes_fc_tx.v24
1 files changed, 24 insertions, 0 deletions
diff --git a/fpga/usrp2/serdes/serdes_fc_tx.v b/fpga/usrp2/serdes/serdes_fc_tx.v
new file mode 100644
index 000000000..2fe967c8d
--- /dev/null
+++ b/fpga/usrp2/serdes/serdes_fc_tx.v
@@ -0,0 +1,24 @@
+
+
+module serdes_fc_tx
+ (input clk, input rst,
+ input xon_rcvd, input xoff_rcvd, output reg inhibit_tx);
+
+ // XOFF means stop sending, XON means start sending
+ // clock domain stuff happens elsewhere, everything here is on main clk
+
+ reg [15:0] state;
+ always @(posedge clk)
+ if(rst)
+ state <= 0;
+ else if(xoff_rcvd)
+ state <= 255;
+ else if(xon_rcvd)
+ state <= 0;
+ else if(state !=0)
+ state <= state - 1;
+
+ always @(posedge clk)
+ inhibit_tx <= (state != 0);
+
+endmodule // serdes_fc_tx