manta/test/test_uart_bridge_sim.py

72 lines
1.8 KiB
Python

from amaranth import *
from amaranth.lib import wiring
from amaranth.lib.wiring import In, Out
from cobs import cobs
from manta import *
from manta.uart import UARTInterface
from manta.utils import *
class UARTHardwarePlusMemoryCore(wiring.Component):
rx: In(1)
tx: Out(1)
def elaborate(self, platform):
m = Module()
m.submodules.uart = uart = UARTInterface(
port="None",
baudrate=1e6,
clock_freq=10e6,
)
m.submodules.mem_core = mem_core = MemoryCore("bidirectional", 32, 1024)
mem_core.base_addr = 0
# Expose the UARTInterface externally, so tests can grab
# the _clocks_per_baud attribute
self.uart = uart
m.d.comb += uart.bus_i.eq(mem_core.bus_o)
m.d.comb += mem_core.bus_i.eq(uart.bus_o)
m.d.comb += self.tx.eq(uart.tx)
m.d.comb += uart.rx.eq(self.rx)
return m
uart_hw = UARTHardwarePlusMemoryCore()
async def send_byte(ctx, module, data):
# 8N1 serial, LSB sent first
data_bits = "0" + f"{data:08b}"[::-1] + "1"
data_bits = [int(bit) for bit in data_bits]
for i in range(10 * uart_hw.uart._clocks_per_baud):
bit_index = i // uart_hw.uart._clocks_per_baud
ctx.set(module.rx, data_bits[bit_index])
await ctx.tick()
@simulate(uart_hw)
async def test_read_request(ctx):
addr = 0x5678_9ABC
header = EthernetMessageHeader.from_params(
MessageTypes.READ_REQUEST, seq_num=0x0, length=1
)
request = bytestring_from_ints([header.as_bits(), addr], byteorder="little")
encoded = cobs.encode(request)
encoded = encoded + int(0).to_bytes(1)
ctx.set(uart_hw.rx, 1)
await ctx.tick()
await ctx.tick()
await ctx.tick()
for byte in encoded:
await send_byte(ctx, uart_hw, int(byte))
print(hex(int(byte)))
await ctx.tick()