def test_program_counter_wraps():
cpu = Computer()
program = [0xFE] * 256
cpu.switches.load_program(program)
for _ in range(957):
cpu.step(debug=False)
def test_opcode_ota():
pc = Computer()
program = [
0xF6, # 0x00 OTA
]
pc.switches.load_program(program)
pc.reg_a.value = 0xF8
pc.step(instructionwise=True)
assert pc.reg_o.value == 0xF8
def test_opcode_lda_immediate():
pc = Computer()
program = [
0x20,
0x02, # 0x00 LDA 02H
]
pc.switches.load_program(program)
pc.step(instructionwise=True, debug=True)
assert pc.reg_a.value == 0x02
def test_opcode_add_immediate():
pc = Computer()
program = [
0x21,
0x3, # 0x00 ADD 02H
]
pc.switches.load_program(program)
pc.reg_a.value = 0xCC
pc.step(instructionwise=True)
assert pc.reg_a.value == 0xCF
def test_opcode_sub():
pc = Computer()
program = [
0x02,
0x02, # 0x00 SUB 02H
0x22, # 0x02 22H
]
pc.switches.load_program(program)
pc.reg_a.value = 0xCC
pc.step(instructionwise=True)
assert pc.reg_a.value == 0xAA
def test_opcode_add_absolute():
pc = Computer()
program = [
0x01,
0x02, # 0x00 ADD 02H
0x22, # 0x02 22H
]
pc.switches.load_program(program)
pc.reg_a.value = 0xCC
pc.step(instructionwise=True)
assert pc.reg_a.value == 0xEE
def test_computer_halts():
pc = Computer()
program = [
0xFE, # 0x00 NOP
0xFE, # 0x01 NOP
0xFE, # 0x02 NOP
0xFF, # 0x03 HLT
0xFE, # 0x04 NOP
0xFE, # 0x05 NOP
0xFE, # 0x06 NOP
]
pc.switches.load_program(program)
counterprogress = [0, 1, 2, 3, 3, 3, 3]
for counter_value in counterprogress:
assert pc.pc.value == counter_value
pc.step(instructionwise=True)
def test_opcode_lda_indirect():
pc = Computer()
program = [
0x10,
0x02, # 0x00 LDA ($02)
0x07, # 0x02 $07
0x22, # 0x03 $22
0x23, # 0x04 $23
0x24, # 0x05 $24
0x25, # 0x06 $25
0x26, # 0x07 $26
0x27, # 0x08 $27
]
pc.switches.load_program(program)
program_counter = pc.pc.value
pc.step(instructionwise=True, debug=True)
assert pc.reg_a.value == 0x26
assert program_counter + 2 == pc.pc.value # two byte instruction
def test_opcode_sta_indirect():
pc = Computer()
program = [
0x20,
0x09, # 0x00 LDA $09
0x45,
0x04, # 0x02 STA ($04)
0x07, # 0x04 $22
0x23, # 0x05 $23
0x24, # 0x06 $24
0x25, # 0x07 $25
0x26, # 0x08 $26
0x27, # 0x09 $27
0x28, # 0x0A $28
0x29, # 0x0B $29
]
pc.switches.load_program(program)
pc.step(instructionwise=True)
assert pc.reg_a.value == 0x09
program_counter = pc.pc.value
pc.step(instructionwise=True)
assert program_counter + 2 == pc.pc.value # two byte instruction
assert pc.mar.value == 0x07
assert pc.ram.data(con=['er']) == 0x09
# don't corrupt other memory
pc.mar.clock(data=0x04, con=['lm'])
assert pc.ram.data(con=['er']) == 0x07
def test_opcode_sta_absolute():
pc = Computer()
program = [
0x20,
0x09, # 0x00 LDA $09
0x35,
0x04, # 0x02 STA $04
0x07, # 0x04 $22
0x23, # 0x05 $23
0x24, # 0x06 $24
0x25, # 0x07 $25
0x26, # 0x08 $26
0x27, # 0x09 $27
0x28, # 0x0A $28
0x29, # 0x0B $29
]
pc.switches.load_program(program)
pc.step(instructionwise=True)
assert pc.reg_a.value == 0x09
program_counter = pc.pc.value
pc.step(instructionwise=True)
assert program_counter + 2 == pc.pc.value # two byte instruction
assert pc.mar.value == 0x04
assert pc.ram.data(con=['er']) == 0x09
def test_opcode_program_sequence():
pc = Computer()
program = [
0x00,
0x06, # 0x00 LDA 06H
0x01,
0x07, # 0x02 ADD 07H
0xF6, # 0x04 OTA
0xFF, # 0x05 HLT
0xA1, # 0x06 A1H
0x22, # 0x07 22H
]
pc.switches.load_program(program)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
assert pc.reg_o.value == 0xC3
def test_opcode_jmp_immediate():
pc = Computer()
program = [
0x00,
0x07, # 0x00 LDA 07H
0x01,
0x08, # 0x20 ADD 08H
0xF6, # 0x04 OTA
0x34,
0x02, # 0x05 JMP $02H
0x00, # 0x07 A1H
0x03, # 0x08 22H
]
pc.switches.load_program(program)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
assert pc.reg_o.value == 0x03
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
assert pc.reg_o.value == 0x06
pc.step(instructionwise=True)
pc.step(instructionwise=True)
pc.step(instructionwise=True)
assert pc.reg_o.value == 0x09
pc.step(instructionwise=True)