Files
taxi/src/eth/example/AC701/fpga/rtl/fpga.sv
Alex Forencich 379a5f3b67 eth: Add Ethernet example design for AC701
Signed-off-by: Alex Forencich <alex@alexforencich.com>
2026-04-13 14:59:37 -07:00

370 lines
6.8 KiB
Systemverilog

// SPDX-License-Identifier: MIT
/*
Copyright (c) 2014-2026 FPGA Ninja, LLC
Authors:
- Alex Forencich
*/
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* FPGA top-level module
*/
module fpga #
(
// simulation (set to avoid vendor primitives)
parameter logic SIM = 1'b0,
// vendor ("GENERIC", "XILINX", "ALTERA")
parameter string VENDOR = "XILINX",
// device family
parameter string FAMILY = "artix7",
// Use 90 degree clock for RGMII transmit
parameter logic USE_CLK90 = 1'b1
)
(
/*
* Clock: 200MHz
* Reset: Push button, active high
*/
input wire logic clk_200mhz_p,
input wire logic clk_200mhz_n,
input wire logic reset,
/*
* GPIO
*/
input wire logic btnu,
input wire logic btnl,
input wire logic btnd,
input wire logic btnr,
input wire logic btnc,
input wire logic [3:0] sw,
output wire logic [3:0] led,
/*
* UART: 115200 bps, 8N1
*/
input wire logic uart_rxd,
output wire logic uart_txd,
input wire logic uart_rts,
output wire logic uart_cts,
/*
* I2C
*/
inout wire logic i2c_scl,
inout wire logic i2c_sda,
output wire logic i2c_mux_reset,
/*
* Ethernet: 1000BASE-T RGMII
*/
input wire logic phy_rx_clk,
input wire logic [3:0] phy_rxd,
input wire logic phy_rx_ctl,
output wire logic phy_tx_clk,
output wire logic [3:0] phy_txd,
output wire logic phy_tx_ctl,
output wire logic phy_reset_n
);
// Clock and reset
wire clk_200mhz_ibufg;
// Internal 125 MHz clock
wire clk_mmcm_out;
wire clk_int;
wire clk90_mmcm_out;
wire clk90_int;
wire rst_int;
wire clk_200mhz_mmcm_out;
wire clk_200mhz_int;
wire mmcm_rst = reset;
wire mmcm_locked;
wire mmcm_clkfb;
IBUFGDS
clk_200mhz_ibufgds_inst(
.I(clk_200mhz_p),
.IB(clk_200mhz_n),
.O(clk_200mhz_ibufg)
);
// MMCM instance
MMCME2_BASE #(
// 200 MHz input
.CLKIN1_PERIOD(5.0),
.REF_JITTER1(0.010),
// 200 MHz input / 1 = 200 MHz PFD (range 10 MHz to 550 MHz)
.DIVCLK_DIVIDE(1),
// 200 MHz PFD * 5 = 1000 MHz VCO (range 600 MHz to 1200 MHz)
.CLKFBOUT_MULT_F(5),
.CLKFBOUT_PHASE(0),
// 1000 MHz VCO / 8 = 125 MHz, 0 degrees
.CLKOUT0_DIVIDE_F(8),
.CLKOUT0_DUTY_CYCLE(0.5),
.CLKOUT0_PHASE(0),
// 1000 MHz VCO / 8 = 125 MHz, 90 degrees
.CLKOUT1_DIVIDE(8),
.CLKOUT1_DUTY_CYCLE(0.5),
.CLKOUT1_PHASE(90),
// 1000 MHz VCO / 5 = 200 MHz, 0 degrees
.CLKOUT2_DIVIDE(5),
.CLKOUT2_DUTY_CYCLE(0.5),
.CLKOUT2_PHASE(0),
// Not used
.CLKOUT3_DIVIDE(1),
.CLKOUT3_DUTY_CYCLE(0.5),
.CLKOUT3_PHASE(0),
// Not used
.CLKOUT4_DIVIDE(1),
.CLKOUT4_DUTY_CYCLE(0.5),
.CLKOUT4_PHASE(0),
.CLKOUT4_CASCADE("FALSE"),
// Not used
.CLKOUT5_DIVIDE(1),
.CLKOUT5_DUTY_CYCLE(0.5),
.CLKOUT5_PHASE(0),
// Not used
.CLKOUT6_DIVIDE(1),
.CLKOUT6_DUTY_CYCLE(0.5),
.CLKOUT6_PHASE(0),
// optimized bandwidth
.BANDWIDTH("OPTIMIZED"),
// don't wait for lock during startup
.STARTUP_WAIT("FALSE")
)
clk_mmcm_inst (
// 200 MHz input
.CLKIN1(clk_200mhz_ibufg),
// direct clkfb feeback
.CLKFBIN(mmcm_clkfb),
.CLKFBOUT(mmcm_clkfb),
.CLKFBOUTB(),
// 125 MHz, 0 degrees
.CLKOUT0(clk_mmcm_out),
.CLKOUT0B(),
// 125 MHz, 90 degrees
.CLKOUT1(clk90_mmcm_out),
.CLKOUT1B(),
// 200 MHz, 0 degrees
.CLKOUT2(clk_200mhz_mmcm_out),
.CLKOUT2B(),
// Not used
.CLKOUT3(),
.CLKOUT3B(),
// Not used
.CLKOUT4(),
// Not used
.CLKOUT5(),
// Not used
.CLKOUT6(),
// reset input
.RST(mmcm_rst),
// don't power down
.PWRDWN(1'b0),
// locked output
.LOCKED(mmcm_locked)
);
BUFG
clk_bufg_inst (
.I(clk_mmcm_out),
.O(clk_int)
);
BUFG
clk90_bufg_inst (
.I(clk90_mmcm_out),
.O(clk90_int)
);
BUFG
clk_200mhz_bufg_inst (
.I(clk_200mhz_mmcm_out),
.O(clk_200mhz_int)
);
taxi_sync_reset #(
.N(4)
)
sync_reset_inst (
.clk(clk_int),
.rst(~mmcm_locked),
.out(rst_int)
);
// GPIO
wire btnu_int;
wire btnl_int;
wire btnd_int;
wire btnr_int;
wire btnc_int;
wire [3:0] sw_int;
taxi_debounce_switch #(
.WIDTH(9),
.N(4),
.RATE(125000)
)
debounce_switch_inst (
.clk(clk_int),
.rst(rst_int),
.in({btnu,
btnl,
btnd,
btnr,
btnc,
sw}),
.out({btnu_int,
btnl_int,
btnd_int,
btnr_int,
btnc_int,
sw_int})
);
wire uart_rxd_int;
wire uart_rts_int;
taxi_sync_signal #(
.WIDTH(2),
.N(2)
)
sync_signal_inst (
.clk(clk_int),
.in({uart_rxd, uart_rts}),
.out({uart_rxd_int, uart_rts_int})
);
wire [3:0] led_int;
// I2C
wire i2c_scl_i;
wire i2c_scl_o;
wire i2c_sda_i;
wire i2c_sda_o;
assign i2c_scl_i = i2c_scl;
assign i2c_scl = i2c_scl_o ? 1'bz : 1'b0;
assign i2c_sda_i = i2c_sda;
assign i2c_sda = i2c_sda_o ? 1'bz : 1'b0;
wire [3:0] phy_rxd_int;
wire phy_rx_ctl_int;
// IODELAY elements for RGMII interface to PHY
IDELAYCTRL
idelayctrl_inst (
.REFCLK(clk_200mhz_int),
.RST(rst_int),
.RDY()
);
for (genvar n = 0; n < 4; n = n + 1) begin : phy_rxd_idelay_bit
IDELAYE2 #(
.IDELAY_TYPE("FIXED")
)
idelay_inst (
.IDATAIN(phy_rxd[n]),
.DATAOUT(phy_rxd_int[n]),
.DATAIN(1'b0),
.C(1'b0),
.CE(1'b0),
.INC(1'b0),
.CINVCTRL(1'b0),
.CNTVALUEIN(5'd0),
.CNTVALUEOUT(),
.LD(1'b0),
.LDPIPEEN(1'b0),
.REGRST(1'b0)
);
end
IDELAYE2 #(
.IDELAY_TYPE("FIXED")
)
phy_rx_ctl_idelay (
.IDATAIN(phy_rx_ctl),
.DATAOUT(phy_rx_ctl_int),
.DATAIN(1'b0),
.C(1'b0),
.CE(1'b0),
.INC(1'b0),
.CINVCTRL(1'b0),
.CNTVALUEIN(5'd0),
.CNTVALUEOUT(),
.LD(1'b0),
.LDPIPEEN(1'b0),
.REGRST(1'b0)
);
fpga_core #(
.SIM(SIM),
.VENDOR(VENDOR),
.FAMILY(FAMILY),
.USE_CLK90(USE_CLK90)
)
core_inst (
/*
* Clock: 125MHz
* Synchronous reset
*/
.clk(clk_int),
.clk90(clk90_int),
.rst(rst_int),
/*
* GPIO
*/
.btnu(btnu_int),
.btnl(btnl_int),
.btnd(btnd_int),
.btnr(btnr_int),
.btnc(btnc_int),
.sw(sw_int),
.led(led_int),
/*
* UART: 115200 bps, 8N1
*/
.uart_rxd(uart_rxd_int),
.uart_txd(uart_txd),
.uart_rts(uart_rts_int),
.uart_cts(uart_cts),
/*
* I2C
*/
.i2c_scl_i(i2c_scl_i),
.i2c_scl_o(i2c_scl_o),
.i2c_sda_i(i2c_sda_i),
.i2c_sda_o(i2c_sda_o),
/*
* Ethernet: 1000BASE-T RGMII
*/
.phy_rx_clk(phy_rx_clk),
.phy_rxd(phy_rxd_int),
.phy_rx_ctl(phy_rx_ctl_int),
.phy_tx_clk(phy_tx_clk),
.phy_txd(phy_txd),
.phy_tx_ctl(phy_tx_ctl),
.phy_reset_n(phy_reset_n)
);
endmodule
`resetall