moved into subdir

1 files changed, 177 insertions, 0 deletions

diff --git a/usrp2/simple_gemac/simple_gemac_rx.v b/usrp2/simple_gemac/simple_gemac_rx.v
new file mode 100644
index 000000000..b02bb0758
--- /dev/null
+++ b/usrp2/simple_gemac/simple_gemac_rx.v
@@ -0,0 +1,177 @@
+
+
+module simple_gemac_rx
+  (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 reg rx_valid, output rx_error, output reg rx_ack,
+   input [47:0] ucast_addr, input [47:0] mcast_addr, 
+   input pass_ucast, input pass_mcast, input pass_bcast, input pass_pause, input pass_all,
+   output reg [15:0] pause_quanta_rcvd, output pause_rcvd,
+   output [31:0] debug );
+
+   localparam RX_IDLE 		  = 0;
+   localparam RX_PREAMBLE 	  = 1;
+   localparam RX_FRAME 		  = 2;
+   localparam RX_GOODFRAME 	  = 3;
+   localparam RX_DO_PAUSE 	  = 4;
+   localparam RX_ERROR 		  = 5;
+   localparam RX_DROP 		  = 6;
+
+   localparam RX_PAUSE 		  = 16;
+   localparam RX_PAUSE_CHK88 	  = RX_PAUSE + 5;
+   localparam RX_PAUSE_CHK08 	  = RX_PAUSE_CHK88 + 1;
+   localparam RX_PAUSE_CHK00 	  = RX_PAUSE_CHK08 + 1;
+   localparam RX_PAUSE_CHK01 	  = RX_PAUSE_CHK00 + 1;
+   localparam RX_PAUSE_STORE_MSB  = RX_PAUSE_CHK01 + 1;
+   localparam RX_PAUSE_STORE_LSB  = RX_PAUSE_STORE_MSB + 1;
+   localparam RX_PAUSE_WAIT_CRC   = RX_PAUSE_STORE_LSB + 1;
+   
+   reg [7:0] 	     rxd_d1;
+   reg rx_dv_d1, rx_er_d1;
+   assign rx_clk     = GMII_RX_CLK;
+   
+   always @(posedge rx_clk)
+     begin
+	rx_dv_d1    <= GMII_RX_DV;
+	rx_er_d1    <= GMII_RX_ER;
+	rxd_d1 	    <= GMII_RXD;
+     end
+
+   reg [7:0] rx_state;
+   wire [7:0] rxd_del;
+   wire rx_dv_del, rx_er_del;
+   reg go_filt;
+   
+   wire match_crc;
+   wire clear_crc 	 = rx_state == RX_IDLE;
+   wire calc_crc 	 = (rx_state == RX_FRAME) | rx_state[7:4]==4'h1;
+
+   localparam DELAY  = 6;
+   delay_line #(.WIDTH(10)) rx_delay
+     (.clk(rx_clk), .delay(DELAY), .din({rx_dv_d1,rx_er_d1,rxd_d1}),.dout({rx_dv_del,rx_er_del,rxd_del}));
+
+   always @(posedge rx_clk)
+     if(reset)
+       rx_ack 	   <= 0;
+     else
+       rx_ack <= (rx_state == RX_GOODFRAME);
+
+   wire is_ucast, is_bcast, is_mcast, is_pause;
+   wire keep_packet  = (pass_ucast & is_ucast) | (pass_mcast & is_mcast) | 
+	(pass_bcast & is_bcast) | (pass_pause & is_pause) | pass_all;
+   
+   assign rx_data   = rxd_del;
+   assign rx_error  = (rx_state == RX_ERROR);
+
+   always @(posedge rx_clk)
+     if(reset)
+       rx_valid <= 0;
+     else if(keep_packet)
+       rx_valid <= 1;
+     else if((rx_state == RX_IDLE)|(rx_state == RX_ERROR))
+       rx_valid <= 0;
+   
+   address_filter af_ucast (.clk(rx_clk), .reset(reset), .go(go_filt), .data(rxd_d1),
+			    .address(ucast_addr), .match(is_ucast), .done());
+   address_filter af_mcast (.clk(rx_clk), .reset(reset), .go(go_filt), .data(rxd_d1),
+			    .address(mcast_addr), .match(is_mcast), .done());
+   address_filter af_bcast (.clk(rx_clk), .reset(reset), .go(go_filt), .data(rxd_d1),
+			    .address(48'hFFFF_FFFF_FFFF), .match(is_bcast), .done());
+   address_filter af_pause (.clk(rx_clk), .reset(reset), .go(go_filt), .data(rxd_d1),
+			    .address(48'h0180_c200_0001), .match(is_pause), .done());
+
+   always @(posedge rx_clk)
+     go_filt 			 <= (rx_state==RX_PREAMBLE) & (rxd_d1 == 8'hD5);
+
+   reg [15:0] pkt_len_ctr;
+   always @(posedge rx_clk)
+     if(reset |(rx_state == RX_IDLE))
+       pkt_len_ctr 	<= 0;
+     else
+       pkt_len_ctr 	<= pkt_len_ctr + 1;
+
+   localparam MIN_PAUSE_LEN = 71;  // 6
+   wire pkt_long_enough  = (pkt_len_ctr >= MIN_PAUSE_LEN);
+   always @(posedge rx_clk)
+     if(reset)
+       rx_state 	<= RX_IDLE;
+     else
+       if(rx_er_d1) // | (~pkt_long_enough & ~rx_dv_d1) & (rx_state != RX_IDLE))
+	 rx_state 	<= RX_ERROR;
+       else
+	 case(rx_state)
+	   RX_IDLE :
+	     if(rx_dv_d1)
+	       if(rxd_d1 == 8'h55)
+		 rx_state   <= RX_PREAMBLE;
+	       else
+		 rx_state   <= RX_ERROR;
+	   RX_PREAMBLE :
+	     if(~rx_dv_d1)
+	       rx_state   <= RX_ERROR;
+	     else if(rxd_d1 == 8'hD5)
+	       rx_state   <= RX_FRAME;
+	     else if(rxd_d1 != 8'h55)
+	       rx_state   <= RX_ERROR;
+	   RX_FRAME :
+	     if(is_pause)
+	       rx_state <= RX_PAUSE;
+	     else if(~rx_dv_d1)
+	       if(match_crc)
+		 rx_state <= RX_GOODFRAME;
+	       else
+		 rx_state <= RX_ERROR;
+	   RX_PAUSE_CHK88 :
+	     if(rxd_d1 != 8'h88)
+	       rx_state <= RX_DROP;
+	     else
+	       rx_state <= RX_PAUSE_CHK08;
+	   RX_PAUSE_CHK08 :
+	     if(rxd_d1 != 8'h08)
+	       rx_state <= RX_DROP;
+	     else
+	       rx_state <= RX_PAUSE_CHK00;
+	   RX_PAUSE_CHK00 :
+	     if(rxd_d1 != 8'h00)
+	       rx_state <= RX_DROP;
+	     else
+	       rx_state <= RX_PAUSE_CHK01;
+	   RX_PAUSE_CHK01 :
+	     if(rxd_d1 != 8'h01)
+	       rx_state <= RX_DROP;
+	     else
+	       rx_state <= RX_PAUSE_STORE_MSB;
+	   RX_PAUSE_WAIT_CRC :
+	     if(pkt_long_enough)
+	       if(match_crc)
+		 rx_state <= RX_DO_PAUSE;
+	       else
+		 rx_state <= RX_DROP;
+	   RX_DO_PAUSE :
+	     rx_state <= RX_IDLE;
+	   RX_GOODFRAME :
+	     rx_state <= RX_IDLE;
+	   RX_DROP, RX_ERROR :
+	     if(~rx_dv_d1)
+	       rx_state <= RX_IDLE;
+	   default
+	     rx_state <= rx_state + 1;
+	 endcase // case (rx_state)
+
+   assign pause_rcvd = (rx_state == RX_DO_PAUSE);
+   crc crc_check(.clk(rx_clk),.reset(reset),.clear(clear_crc),
+		 .data(rxd_d1),.calc(calc_crc),.crc_out(),.match(match_crc));
+
+   always @(posedge rx_clk)
+     if(reset)
+       pause_quanta_rcvd <= 0;
+     else if(rx_state == RX_PAUSE_STORE_MSB)
+       pause_quanta_rcvd[15:8] <= rxd_d1;
+     else if(rx_state == RX_PAUSE_STORE_LSB)
+       pause_quanta_rcvd[7:0] <= rxd_d1;
+   
+   assign rx_clk 	  = GMII_RX_CLK;
+
+   assign debug = rx_state;
+   
+endmodule // simple_gemac_rx