we now inhibit our own sending when a received pause frame comes. _rx.v is currently only a skeleton for testing pause

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@10721 221aa14e-8319-0410-a670-987f0aec2ac5

5 files changed, 66 insertions, 14 deletions

diff --git a/usrp2/fpga/simple_gemac/flow_ctrl_tx.v b/usrp2/fpga/simple_gemac/flow_ctrl_tx.v
index 9f7556de4..f80f5a76d 100644
--- a/usrp2/fpga/simple_gemac/flow_ctrl_tx.v
+++ b/usrp2/fpga/simple_gemac/flow_ctrl_tx.v
@@ -11,13 +11,16 @@ module flow_ctrl_tx
    input        pause_quanta_val,

    // MAC_tx_ctrl

    output       pause_apply,

-   input        pause_quanta_sub);

+   input        paused);

      

    // ******************************************************************************        

    // Inhibit our TX from transmitting because they sent us a PAUSE frame

    // ******************************************************************************

 

-   reg [15:0] 	pause_quanta_counter;

+   // Pauses are in units of 512 bit times, or 64 bytes/clock cycles, and can be

+   //   as big as 16 bits, so 22 bits are needed for the counter

+   

+   reg [15+6:0] pause_quanta_counter;

    reg 		pqval_d1, pqval_d2;		

 

    always @(posedge tx_clk) pqval_d1 <= pause_quanta_val;

@@ -27,8 +30,8 @@ module flow_ctrl_tx
      if (rst)

        pause_quanta_counter <= 0;

      else if (pqval_d1 & ~pqval_d2)

-       pause_quanta_counter <= pause_quanta; 

-     else if((pause_quanta_counter!=0) & pause_quanta_sub)

+       pause_quanta_counter <= {pause_quanta, 6'b0}; 

+     else if((pause_quanta_counter!=0) & paused)

        pause_quanta_counter <= pause_quanta_counter - 1;

 

    assign	pause_apply = tx_pause_en & (pause_quanta_counter != 0);

diff --git a/usrp2/fpga/simple_gemac/simple_gemac.v b/usrp2/fpga/simple_gemac/simple_gemac.v
index 0769fe615..e6f9c982a 100644
--- a/usrp2/fpga/simple_gemac/simple_gemac.v
+++ b/usrp2/fpga/simple_gemac/simple_gemac.v
@@ -31,24 +31,24 @@ module simple_gemac
       .tx_clk(tx_clk), .tx_data(tx_data), .tx_valid(tx_valid), .tx_error(tx_error), .tx_ack(tx_ack),
       .ifg(SGE_IFG), .mac_addr(48'hF1_F2_F3_F4_F5_F6),
       .pause_req(pause_req), .pause_time(pause_time),  // We request flow control
-      .pause_apply(pause_apply), .pause_applied(pause_applied)  // We respect flow control
+      .pause_apply(pause_apply), .paused(paused)  // We respect flow control
       );
-/*
+
    simple_gemac_rx simple_gemac_rx
      (.reset(rst_rxclk),
       .GMII_RX_CLK(GMII_RX_CLK), .GMII_RX_DV(GMII_RX_DV), 
       .GMII_RX_ER(GMII_RX_ER), .GMII_RXD(GMII_RXD),
       .rx_clk(rx_clk), .rx_data(rx_data), .rx_valid(rx_valid), .rx_error(rx_error), .rx_ack(rx_ack),
-      .pause_quanta_rcvd(pause_qanta_rcvd), .pause_rcvd(pause_rcvd) 
+      .pause_quanta_rcvd(pause_quanta_rcvd), .pause_rcvd(pause_rcvd) 
       );
-  */ 
+
    flow_ctrl_tx flow_ctrl_tx
-     (.rst(reset_txclk), .tx_clk(tx_clk),
+     (.rst(rst_txclk), .tx_clk(tx_clk),
       .tx_pause_en(SGE_RESPECT_FLOW_CTRL),
       .pause_quanta(pause_quanta_rcvd), // 16 bit value
       .pause_quanta_val(pause_rcvd),
       .pause_apply(pause_apply),
-      .pause_quanta_sub(pause_applied)
+      .paused(paused)
       );
 
    
diff --git a/usrp2/fpga/simple_gemac/simple_gemac_rx.v b/usrp2/fpga/simple_gemac/simple_gemac_rx.v
new file mode 100644
index 000000000..8650a69a9
--- /dev/null
+++ b/usrp2/fpga/simple_gemac/simple_gemac_rx.v
@@ -0,0 +1,34 @@
+
+
+module simple_gemac_rx
+  (input clk125, input reset,
+   input GMII_RX_CLK, input GMII_RX_DV, input GMII_RX_ER, input [7:0] GMII_RXD,
+   output rx_clk, output [7:0] rx_data, output rx_valid, output rx_error, output rx_ack,
+   output reg [15:0] pause_quanta_rcvd, output reg pause_rcvd );
+
+   
+   
+   initial 
+     begin
+	pause_rcvd    <= 0;
+	pause_quanta_rcvd  = 10;
+	#50000 pause_rcvd <= 1;
+	@(posedge rx_clk)
+	  pause_rcvd <= 0;
+	repeat (100)
+	  @(posedge rx_clk);
+	pause_quanta_rcvd <= 15;
+	pause_rcvd 	  <= 1;
+	@(posedge rx_clk)
+	  pause_rcvd <= 0;
+	repeat (1200)
+	  @(posedge rx_clk);
+	pause_rcvd 	  <= 1;
+	@(posedge rx_clk)
+	  pause_rcvd <= 0;
+	
+     end
+   
+   assign rx_clk 	   = GMII_RX_CLK;
+   
+endmodule // simple_gemac_rx
diff --git a/usrp2/fpga/simple_gemac/simple_gemac_tb.v b/usrp2/fpga/simple_gemac/simple_gemac_tb.v
index 231a8b2ec..481c6ebab 100644
--- a/usrp2/fpga/simple_gemac/simple_gemac_tb.v
+++ b/usrp2/fpga/simple_gemac/simple_gemac_tb.v
@@ -9,7 +9,7 @@ module simple_gemac_tb;
    initial #1000 reset = 0;
    always #50 clk = ~clk;
 
-   wire GMII_RX_DV, GMII_RX_ER, GMII_TX_EN, GMII_TX_ER;
+   wire GMII_RX_DV, GMII_RX_ER, GMII_TX_EN, GMII_TX_ER, GMII_GTX_CLK;
    wire [7:0] GMII_RXD, GMII_TXD;
 
    wire rx_valid, rx_error, rx_ack;
@@ -20,7 +20,13 @@ module simple_gemac_tb;
    reg [7:0] tx_data;
    
    wire [15:0] pause_time = 16'hBEEF;
-   reg pause_req = 0;
+   reg pause_req     = 0;
+
+   reg GMII_RX_CLK;
+   always @(GMII_GTX_CLK)
+     GMII_RX_CLK <= #30 GMII_GTX_CLK;
+   
+//   wire GMII_RX_CLK  = #30 GMII_GTX_CLK;
    
    simple_gemac simple_gemac
      (.clk125(clk),  .reset(reset),
diff --git a/usrp2/fpga/simple_gemac/simple_gemac_tx.v b/usrp2/fpga/simple_gemac/simple_gemac_tx.v
index ffc8f6e99..690fd5c37 100644
--- a/usrp2/fpga/simple_gemac/simple_gemac_tx.v
+++ b/usrp2/fpga/simple_gemac/simple_gemac_tx.v
@@ -5,7 +5,7 @@ module simple_gemac_tx
    output tx_clk, input [7:0] tx_data, input tx_valid, input tx_error, output tx_ack,
    input [7:0] ifg, input [47:0] mac_addr,
    input pause_req, input [15:0] pause_time,
-   input pause_apply, output pause_applied
+   input pause_apply, output reg paused
    );
 
    reg tx_en_pre, tx_er_pre;
@@ -72,7 +72,7 @@ module simple_gemac_tx
 	   if(~in_ifg)
 	     if(send_pause)
 	       tx_state <= TX_PAUSE;
-	     else if(tx_valid)
+	     else if(tx_valid & ~pause_apply)
 	       tx_state <= TX_PREAMBLE;
 	 TX_FIRSTBYTE :
 	   if(tx_error)
@@ -223,6 +223,15 @@ module simple_gemac_tx
 	    GMII_TXD <= txd_pre;
 	endcase // case (tx_state)
      end
+
+   // report that we are paused only when we get back to IDLE
+   always @(posedge tx_clk)
+     if(reset)
+       paused 	     <= 0;
+     else if(~pause_apply)
+       paused 	     <= 0;
+     else if(tx_state == TX_IDLE)
+       paused 	     <= 1;
    
 endmodule // simple_gemac_tx