diff options
Diffstat (limited to 'fpga/usrp2/simple_gemac/simple_gemac_rx.v')
| -rw-r--r-- | fpga/usrp2/simple_gemac/simple_gemac_rx.v | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/fpga/usrp2/simple_gemac/simple_gemac_rx.v b/fpga/usrp2/simple_gemac/simple_gemac_rx.v new file mode 100644 index 000000000..e6c0424bd --- /dev/null +++ b/fpga/usrp2/simple_gemac/simple_gemac_rx.v @@ -0,0 +1,196 @@ +// +// Copyright 2011 Ettus Research LLC +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. +// + + + +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, is_any_ucast; + wire keep_packet = (pass_all & is_any_ucast) | (pass_ucast & is_ucast) | (pass_mcast & is_mcast) | + (pass_bcast & is_bcast) | (pass_pause & is_pause); + + 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()); + address_filter_promisc af_promisc (.clk(rx_clk), .reset(reset), .go(go_filt), .data(rxd_d1), + .match(is_any_ucast), .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 |