HeavyX/examples/helloworld_ecp5.py

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from nmigen import *
from nmigen.back import rtlil
from heavycomps import uart
class Top(Elaboratable):
def __init__(self, baudrate=115200):
self.baudrate = baudrate
self.clk100 = Signal()
self.serial_tx = Signal()
def elaborate(self, platform):
m = Module()
cd_sync = ClockDomain(reset_less=True)
m.domains += cd_sync
m.d.comb += cd_sync.clk.eq(self.clk100)
string = "Hello World!\r\n"
mem = Memory(width=8, depth=len(string),
init=[ord(c) for c in string])
m.submodules.rdport = rdport = mem.read_port(synchronous=False)
wait = Signal()
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tx = uart.RS232TX(round(2**32*self.baudrate/100e6))
m.submodules.tx = tx
m.d.comb += [
tx.stb.eq(~wait),
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tx.data.eq(rdport.data),
self.serial_tx.eq(tx.tx)
]
release = Signal()
counter = Signal(25)
m.d.sync += Cat(counter, release).eq(counter + 1)
with m.If(release):
m.d.sync += wait.eq(0)
with m.If(~wait & tx.ack):
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with m.If(rdport.addr == len(string) - 1):
m.d.sync += rdport.addr.eq(0)
m.d.sync += wait.eq(1)
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with m.Else():
m.d.sync += rdport.addr.eq(rdport.addr + 1)
return m
def main():
top = Top()
output = rtlil.convert(Fragment.get(top, None),
ports=(top.clk100, top.serial_tx))
print(output)
if __name__ == "__main__":
main()