Time to digital test

fabrictdc.py

# Based on https://gist.github.com/newhouseb/784cc0c24f8681c3224c15758be5d1b8
# Connect serial monitor with 115200 baud over the FTDI (might require fixing the FTDI with https://github.com/trabucayre/fixFT2232_ecp5evn)
# WARNING: Maybe this might damage your FPGA (this one seems fine, even after running at 1+ GHz for extended time periods)
# Code for ECP5 EVN board

from amaranth import *
from amaranth.build import *
from amaranth.lib.coding import Decoder
from amaranth_boards import ecp5_5g_evn as FPGA
from amaranth_stdio.serial import AsyncSerial

        
def create_delay_line(m, start: Signal, length):
    def get_slice():
        start_x = 10
        start_y = 11
        slice_i = 0
        while True:
            yield "X{}/Y{}/SLICE{}".format(start_x, start_y, ["A","B","C","D"][slice_i])
            if slice_i == 3:
                start_x += 1
            slice_i = (slice_i + 1) % 4
    gen_slice = get_slice()

    intoff = Signal(length + 1)
    thermometer = Signal(length)
    carry = Signal(length//2 + 1)
    m.submodules.delay_start = Instance("TRELLIS_SLICE",
        a_BEL=next(gen_slice),
        p_MODE="CCU2",
        p_CCU2_INJECT1_0="NO",
        p_CCU2_INJECT1_1="YES",
        p_LUT0_INITVAL=0x00FF,
        p_LUT1_INITVAL=0x00FF,
        i_D1=start,
        o_FCO=carry[0]
    )

    for i in range(length // 2):
        delay = Instance("TRELLIS_SLICE",
            a_BEL=next(gen_slice),

            p_MODE="CCU2",
            p_CCU2_INJECT1_0="NO",
            p_CCU2_INJECT1_1="NO",
            p_LUT0_INITVAL=0x3300,
            p_LUT1_INITVAL=0x3300,
            p_REG0_SD="1",
            p_REG1_SD="1",

            i_B0=0,
            i_B1=0,
            i_LSR=0,

            o_F0=intoff[2*i + 0], # Out of the LUT
            i_DI0=intoff[2*i + 0], # Into the FF
            o_Q0=thermometer[2*i + 0], # Out of the FF

            o_F1=intoff[2*i + 1],
            i_DI1=intoff[2*i + 1], # Not i_F0?
            o_Q1=thermometer[2*i + 1],

            i_FCI=carry[i],
            o_FCO=carry[i+1],

            i_CLK=ClockSignal()
        )
        setattr(m.submodules, "delay_" + str(i), delay)

    return thermometer



class FabricTDC1(Elaboratable):
    def __init__(self):
        pass

    def elaborate(self, platform):
        m = Module()
        
        time = Signal(64)
        
        m.d.sync += time.eq(time + 1)



        intermediate = Signal() # 840 MHz
        fb = Signal()
        test_sig = Signal()
        fb2 = Signal()

        # Adjust this one
        m.submodules += Instance("EHXPLLL",
            a_LOC = "PLL3", # Location, one of PLL0, 1, 2, 3

            p_OUTDIVIDER_MUXA='DIVA',
            p_CLKOP_ENABLE='ENABLED',
            p_CLKOS_ENABLE='ENABLED',

            p_CLKOP_DIV=5, # PLL frequency in 100 MHz steps (in this case 500 MHz)
            p_CLKFB_DIV=1,
            p_CLKI_DIV=1, # Reduce PLL frequency steps to 100 MHz / n

            p_CLKOS_DIV=2, # Output frequency, fed into the delay line, PLL frequency / n (in this case 500 MHz / 2 = 250 MHz)

            p_FEEDBK_PATH='CLKOP',
            i_CLKI=intermediate,
            i_ENCLKOP=1,
            i_ENCLKOS=1,
            o_CLKOS=test_sig,


            i_CLKFB=fb2,
            o_CLKOP=fb2,
            )

        # This PLL outputs a 100 MHz frequency (12 * 25 / 3)
        m.submodules += Instance("EHXPLLL",
            p_OUTDIVIDER_MUXA='DIVA',
            p_CLKOP_ENABLE='ENABLED',
            p_CLKOS_ENABLE='ENABLED',

            p_CLKOP_DIV=25,
            p_CLKFB_DIV=1,
            p_CLKI_DIV=1,

            p_CLKOS_DIV=3,

            p_FEEDBK_PATH='CLKOP',
            i_CLKI=ClockSignal("sync"),
            i_ENCLKOP=1,
            i_ENCLKOS=1,
            o_CLKOS=intermediate,


            i_CLKFB=fb,
            o_CLKOP=fb,
            )

        


        t_len = 512

        thermometer = create_delay_line(m, test_sig, t_len)



        

        m.submodules.uart = uart = AsyncSerial(divisor = int(104), pins = platform.request("uart", 0)) # 115200 Baud


        buffer = Signal(t_len)
        digit = Signal(range(t_len))

        with m.FSM(name="Debug"):
            with m.State("Start"):
                with m.If(uart.tx.rdy):
                    m.d.comb += uart.tx.data.eq(ord("\n"))
                    m.d.comb += uart.tx.ack.eq(1)
                    m.d.sync += buffer.eq(thermometer)
                    m.d.sync += digit.eq(0)
                    m.next = "Wait"
                
            with m.State("Wait"):
                with m.If(uart.tx.rdy & (time[:22] == 0)):
                    m.next = "Send"
            
            with m.State("Send"):
                with m.If(uart.tx.rdy):
                    with m.If(digit == t_len - 1):
                        m.next = "Start"

                    m.d.comb += uart.tx.data.eq(buffer.bit_select(digit, 1) + ord("0"))

                    m.d.comb += uart.tx.ack.eq(1)
                    m.d.sync += digit.eq(digit + 1)
    

        return m




if __name__ == "__main__":
    FPGA.ECP55GEVNPlatform().build(FabricTDC1(), do_program=True, nextpnr_opts="--timing-allow-fail -r")

    with open("build/top.tim") as logfile:
        for line in logfile.read().split("\n"):
            if "test_sig" in line:
                print()
                print("Clock frequency:", line.split("MHz")[0].split()[-1], "MHz")


# Examples:

#11111111111111111010000000000000000000000000000111111111111111111111111111111111111010000000000000000000000000000101111111111111
#11111111111111111111111111111111101000000000000000000000000000000111111111111111111111111111111111101000000000000000000000000000

#11111111111111111111111111111111111010000000000000000000000000000001011111111111111111111111111111111110100000000000000000000000

#11111111111111111110100000000000000000000000000000000000000000011111111111111111111111111111111111111111111110100000000000000000
#00000000000000000001111111111111111111111111111111111111111111111110100000000000000000000000000000000000000000011111111111111111

#11101000000000000000000111111111111111111111111110100000000000000000000111111111111111111111111010000000000000000000010111111111111111111110100000000000000000000000011111111111111111111010000000000000000000000001011111111111111111101000000000000000000000000000111111111111111110000000000000000000000000000001111111111111101000000000000000000000000000000001111111111110100000000000000000000000000000000111111111101000000000000000000000000000000000001111111110101000000000000000000000000000000010101110101000000000
#11111111111111111110100000000000000001111111111111111111101000000000000000000111111111111111111010000000000000000001111111111111111110100000000000000000000111111111111111101000000000000000000000011111111111111010000000000000000000000011111111111110100000000000000000000000001011111111101000000000000000000000000000101110111010000000000000000000000000000010101010100000000000000000000000000000101010100000000000000000000000000000000000101000000000000000000000000000000000000000000000000000000000000000000000000000
#00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001011111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
#11111111101000000000000001111111111111111111101000000000000000011111111111111111101000000000000000000111111111111111101000000000000000000001111111111111101000000000000000000001111111111111111010000000000000000000001111111111101010000000000000000000000011111111111010000000000000000000000000101011111010000000000000000000000000000010101010100000000000000000000000000000101010100000000000000000000000000000100010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#11101000000000000001111111111111111110100000000000000011111111111111111110100000000000000001111111111111111010000000000000000001111111111111101000000000000000000000111111111111101000000000000000000001111111111110100000000000000000000000101111111110100000000000000000000000001010111010100000000000000000000000001010101010000000000000000000000000000010101000000000000000000000000000000010101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#11111111111111111111111110100000000000000000000000000111111111111111111111111110100000000000000000000000000001111111111111111111111010000000000000000000000000000000001111111111111111111010100000000000000000000000000000000101111111111111111010000000000000000000000000000000000000011111111111111110100000000000000000000000000000000000000011111111111010000000000000000000000000000000000000000011111111111010000000000000000000000000000000000000000000111111111110000000000000000000000000000000000000000000101111101000

#00000000101111111010000000000000000000000000101110101000000000000000000000000000101010100000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00000000000000000000000011111111101000000000000000000000000010111110111000000000000000000000000000101011101000000000000000000000000000000010101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#10100000000000000000001111111111111010000000000000000000001111111111111000000000000000000000001111111111100000000000000000000000001010111010100000000000000000000000001010101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00000000001111111111111111111000000000000001111111111111111110100000000000001111111111111111111010000000000001111111111111111010000000000000000011111111111110101000000000000000111111111111111010000000000000000001111111111110100000000000000000000011111111101000000000000000000000001010101010000000000000000000000000101010100000000000000000000000000010101010000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00000000000000000010101110100000000000000000000000001010101010000000000000000000000000001010100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00001111111111101000000000000000000011111111111000000000000000000000111111101000000000000000000000001011101010000000000000000000000000101010000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00000011111111111010000000000000000010111111111010000000000000000000101011101000000000000000000000001010101000000000000000000000000000101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#00000011111111111000000000000000000000111111111000000000000000000000101011101000000000000000000000001010101000000000000000000000000010101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#11111110000000000000000000111111111110100000000000000000000010101110100000000000000000000000001010101000000000000000000000000000101000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

#11111111111111111000000000000000000000000001011111111111111111111111111000000000000000000000000000011111111111111111111111101000000000000000000000000000000111111111111111111111101000000000000000000000000000000001111111111111111111101000000000000000000000000000000000011111111111111111101000000000000000000000000000000000000001111111111111101000000000000000000000000000000000000000111111111111100000000000000000000000000000000000000000001111111111101000000000000000000000000000000000000000111111111110100000000000

#11111111111111101000000000000000000000000001111111111111111111111110101000000000000000000000000000011111111111111111111111101000000000000000000000000000000111111111111111111110100000000000000000000000000000000001111111111111111111101000000000000000000000000000000000011111111111111111101000000000000000000000000000000000000011111111111111101000000000000000000000000000000000000001111111111111100000000000000000000000000000000000000000001111111111100000000000000000000000000000000000000000111111111010000000000000

#11111111111111111111111111111111111111111111111111111000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111010100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111101000000000000000000000000000