Files
verilog6502/sim/verilog6502_32bit_test.py
2026-04-26 21:03:53 -07:00

208 lines
6.7 KiB
Python

import cocotb
from cocotb.handle import Immediate
from cocotb.clock import Clock
from cocotb.triggers import Timer, RisingEdge
from collections import defaultdict
CLK_PERIOD = 5
memory = defaultdict(int)
def write_dword(addr: int, data: int):
memory[addr + 0] = (data >> 0) & 0xff
memory[addr + 1] = (data >> 8) & 0xff
memory[addr + 2] = (data >> 16) & 0xff
memory[addr + 3] = (data >> 24) & 0xff
def write_byte(addr: int, data: int):
memory[addr] = data & 0xff
def write_bytes(addr: int, data: bytes| list[int]):
for i, val in enumerate(data):
memory[addr + i] = int(val)
async def handle_memory(dut):
while True:
await RisingEdge(dut.clk)
addr = int(dut.AB.value)
we = bool(dut.WE.value)
dut.DI.value = memory[addr]
if we:
memory[addr] = int(dut.DO.value)
@cocotb.test
async def test_reset(dut):
cocotb.start_soon(Clock(dut.clk, CLK_PERIOD, unit="ns").start())
cocotb.start_soon(handle_memory(dut))
write_dword(0xfffffff4, 0x12345678)
dut.RDY.value = Immediate(1)
dut.reset.value = Immediate(1)
for _ in range(10):
await RisingEdge(dut.clk)
dut.reset.value = 0
expected_cpu_outputs = [
(0x00000100, True, (int(dut.PC.value) >> 24) & 0xff), # High addr
(0x000001ff, True, (int(dut.PC.value) >> 16) & 0xff), # Mid high addr
(0x000001fe, True, (int(dut.PC.value) >> 8) & 0xff), # Mid low addr
(0x000001fd, True, (int(dut.PC.value) >> 0) & 0xff), # Low addr
(0x000001fc, True, int(dut.P.value)), # Status
(0xfffffff4, False, int(dut.regfile.value)), # read vector byte 0
(0xfffffff5, False, int(dut.regfile.value)), # read vector byte 1
(0xfffffff6, False, int(dut.regfile.value)), # read vector byte 2
(0xfffffff7, False, int(dut.regfile.value)), # read vector byte 3
(0x12345678, False, int(dut.regfile.value)), # Read first instruction
(0x12345679, False, int(dut.regfile.value)), # Read second byte
]
for expected_output in expected_cpu_outputs:
await RisingEdge(dut.clk)
expected_addr, expected_we, expected_do = expected_output
dut_addr = int(dut.AB.value)
dut_we = bool(dut.WE.value)
dut_do = int(dut.DO.value)
assert dut_addr == expected_addr
assert dut_we == expected_we
assert dut_do == expected_do
@cocotb.test
async def test_absolute(dut):
cocotb.start_soon(Clock(dut.clk, CLK_PERIOD, unit="ns").start())
cocotb.start_soon(handle_memory(dut))
write_dword(0xfffffff4, 0x200)
# lda $abcd1234
# sta $50515253
# wai
write_bytes(0x200, [0xad, 0x34, 0x12, 0xcd, 0xab])
write_bytes(0x205, [0x8d, 0x53, 0x52, 0x51, 0x50])
write_byte(0x20a, 0xcb)
write_byte(0xabcd1234, 0x55)
dut.RDY.value = Immediate(1)
dut.reset.value = Immediate(1)
for _ in range(10):
await RisingEdge(dut.clk)
dut.reset.value = 0
expected_cpu_outputs = [
None, # ignore reset sequence
None,
None,
None,
None,
None,
None,
None,
None,
(0x00000200, False, None), # Read first instruction
(0x00000201, False, None), # Read address byte 0
(0x00000202, False, None), # Read address byte 1
(0x00000203, False, None), # Read address byte 2
(0x00000204, False, None), # Read address byte 3
(0xabcd1234, False, None), # Read from absolute address
(0x00000205, False, None), # Read second instruction
(0x00000206, False, None), # Read address byte 0
(0x00000207, False, None), # Read address byte 1
(0x00000208, False, None), # Read address byte 2
(0x00000209, False, None), # Read address byte 3
(0x50515253, True, 0x55), # Write to absolute address
]
for expected_output in expected_cpu_outputs:
await RisingEdge(dut.clk)
if expected_output:
expected_addr, expected_we, expected_do = expected_output
dut_addr = int(dut.AB.value)
dut_we = bool(dut.WE.value)
dut_do = int(dut.DO.value)
assert dut_addr == expected_addr
assert dut_we == expected_we
if dut_we:
assert dut_do == expected_do
@cocotb.test
async def test_absolute_x(dut):
cocotb.start_soon(Clock(dut.clk, CLK_PERIOD, unit="ns").start())
cocotb.start_soon(handle_memory(dut))
write_dword(0xfffffff4, 0x200)
# ldx #1
# lda $abcd1234,x
# inx
# sta $01020304,x
# wai
write_bytes(0x200, [0xa2, 0x01])
write_bytes(0x202, [0xbd, 0x34, 0x12, 0xcd, 0xab])
write_bytes(0x207, [0xe8])
write_bytes(0x208, [0x9d, 0x04, 0x03, 0x02, 0x01])
write_byte(0x20d, 0xcb)
write_byte(0xabcd1235, 0xaa)
dut.RDY.value = Immediate(1)
dut.reset.value = Immediate(1)
for _ in range(10):
await RisingEdge(dut.clk)
dut.reset.value = 0
expected_cpu_outputs = [
None, # ignore reset sequence
None,
None,
None,
None,
None,
None,
None,
None,
(0x00000200, False, None), # ldx #1
(0x00000201, False, None), # Immediate
(0x00000202, False, None), # ldx $abcd1234,x
(0x00000203, False, None), # addr 0
(0x00000204, False, None), # addr 1
(0x00000205, False, None), # addr 2
(0x00000206, False, None), # addr 3
(0xabcd1235, False, None), # Read from address
(0x00000207, False, None), # inx
(0x00000208, False, None), # sta $01020304,x
(0x00000208, False, None), # store reg
(0x00000209, False, None), # addr 0
(0x0000020a, False, None), # addr 1
(0x0000020b, False, None), # addr 2
(0x0000020c, False, None), # addr 3
(0x01020306, False, None), # Write to address
(0x01020306, True, 0xaa), # Write to address
]
for expected_output in expected_cpu_outputs:
await RisingEdge(dut.clk)
if expected_output:
expected_addr, expected_we, expected_do = expected_output
dut_addr = int(dut.AB.value)
dut_we = bool(dut.WE.value)
dut_do = int(dut.DO.value)
assert dut_addr == expected_addr
assert dut_we == expected_we
if dut_we:
assert dut_do == expected_do