61 lines
1.8 KiB
Python
61 lines
1.8 KiB
Python
from random import sample
|
|
|
|
from manta.uart import TransmitBridge
|
|
from manta.utils import *
|
|
|
|
bridge_tx = TransmitBridge()
|
|
|
|
|
|
async def verify_encoding(ctx, data, bytes):
|
|
"""
|
|
Place a read response on the internal bus, and verify that the sequence of bytes
|
|
sent from TransmitBridge matches the provided bytestring `bytes`.
|
|
|
|
This function also models an ideal UARTTransmitter module, which begins transmitting
|
|
bytes when `start` is asserted, and reports when it is done by asserting `done`.
|
|
"""
|
|
|
|
# Place a read response on the internal bus
|
|
ctx.set(bridge_tx.data_i, data)
|
|
ctx.set(bridge_tx.valid_i, True)
|
|
ctx.set(bridge_tx.rw_i, 0)
|
|
ctx.set(bridge_tx.done_i, True)
|
|
|
|
await ctx.tick()
|
|
|
|
ctx.set(bridge_tx.data_i, 0)
|
|
ctx.set(bridge_tx.valid_i, False)
|
|
ctx.set(bridge_tx.rw_i, 0)
|
|
|
|
# Model the UARTTransmitter
|
|
sent_bytes = b""
|
|
iters = 0
|
|
|
|
while len(sent_bytes) < len(bytes):
|
|
# If start_o is asserted, set done_i to zero, then delay, then set it back to one
|
|
if ctx.get(bridge_tx.start_o):
|
|
sent_bytes += ctx.get(bridge_tx.data_o).to_bytes(1, "big")
|
|
ctx.set(bridge_tx.done_i, 0)
|
|
|
|
for _ in range(10):
|
|
await ctx.tick()
|
|
|
|
ctx.set(bridge_tx.done_i, 1)
|
|
await ctx.tick()
|
|
|
|
# Time out if not enough bytes after trying to get bytes 15 times
|
|
iters += 1
|
|
if iters > 15:
|
|
raise ValueError("Timed out waiting for bytes.")
|
|
|
|
# Verify bytes sent from ReceiveBridge match expected_bytes
|
|
if sent_bytes != bytes:
|
|
raise ValueError(f"Received {sent_bytes} instead of {bytes}.")
|
|
|
|
|
|
@simulate(bridge_tx)
|
|
async def test_some_random_values(ctx):
|
|
for i in sample(range(0xFFFF), k=5000):
|
|
expected = f"D{i:04X}\r\n".encode("ascii")
|
|
await verify_encoding(ctx, i, expected)
|