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Added 65C02 instruction BIT ZP,X.

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This commit is contained in:
Mike Naberezny 2009-04-08 20:03:12 -07:00
parent ab0758010a
commit 1ebe890ccb
2 changed files with 97 additions and 0 deletions
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5
src/py65/devices/mpu65c02.py
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@ -54,6 +54,11 @@ class MPU(NMOS6502):
self.opAND(self.ZeroPageIndirectAddr)
self.pc += 1
@instruction(name="BIT", mode="zpx", cycles=4)
def inst_0x34(self):
self.opBIT(self.ZeroPageXAddr)
self.pc += 1
@instruction(name="EOR", mode="zpi", cycles=5)
def inst_0x52(self):
self.opEOR(self.ZeroPageIndirectAddr)

92
src/py65/tests/devices/test_mpu65c02.py
View File

@ -113,6 +113,98 @@ class MPUTests(unittest.TestCase, Common6502Tests):
self.assertEquals(mpu.NEGATIVE, mpu.flags & mpu.NEGATIVE)
self.assertEquals(0, mpu.flags & mpu.ZERO)
# BIT (Zero Page)
def test_bit_zp_x_copies_bit_7_of_memory_to_n_flag_when_0(self):
mpu = self._make_mpu()
mpu.flags &= ~(mpu.NEGATIVE)
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0xFF
mpu.x = 0x03
mpu.a = 0xFF
mpu.step()
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(mpu.NEGATIVE, mpu.flags & mpu.NEGATIVE)
def test_bit_zp_x_copies_bit_7_of_memory_to_n_flag_when_1(self):
mpu = self._make_mpu()
mpu.flags &= mpu.NEGATIVE
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0x00
mpu.x = 0x03
mpu.a = 0xFF
mpu.step()
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(0, mpu.flags & mpu.NEGATIVE)
def test_bit_zp_x_copies_bit_6_of_memory_to_v_flag_when_0(self):
mpu = self._make_mpu()
mpu.flags &= ~(mpu.OVERFLOW)
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0xFF
mpu.x = 0x03
mpu.a = 0xFF
mpu.step()
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(mpu.OVERFLOW, mpu.flags & mpu.OVERFLOW)
def test_bit_zp_x_copies_bit_6_of_memory_to_v_flag_when_1(self):
mpu = self._make_mpu()
mpu.flags &= mpu.OVERFLOW
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0x00
mpu.x = 0x03
mpu.a = 0xFF
mpu.step()
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(0, mpu.flags & mpu.OVERFLOW)
def test_bit_zp_x_stores_result_of_and_in_z_while_preserving_a_when_1(self):
mpu = self._make_mpu()
mpu.flags &= mpu.ZERO
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0x00
mpu.x = 0x03
mpu.a = 0x01
mpu.step()
self.assertEquals(mpu.ZERO, mpu.flags & mpu.ZERO)
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(0x01, mpu.a)
self.assertEquals(0x00, mpu.memory[0x0010 + mpu.x])
def test_bit_zp_x_stores_result_of_and_when_nonzero_in_z_while_preserving_a(self):
mpu = self._make_mpu()
mpu.flags &= mpu.ZERO
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0x01
mpu.x = 0x03
mpu.a = 0x01
mpu.step()
self.assertEquals(0, mpu.flags & mpu.ZERO) # result of AND is non-zero
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(0x01, mpu.a)
self.assertEquals(0x01, mpu.memory[0x0010 + mpu.x])
def test_bit_zp_x_stores_result_of_and_when_zero_in_z_while_preserving_a(self):
mpu = self._make_mpu()
mpu.flags &= ~(mpu.ZERO)
self._write(mpu.memory, 0x0000, (0x34, 0x10)) #=> BIT $0010,X
mpu.memory[0x0013] = 0x00
mpu.x = 0x03
mpu.a = 0x01
mpu.step()
self.assertEquals(0x0002, mpu.pc)
self.assertEquals(4, mpu.processorCycles)
self.assertEquals(mpu.ZERO, mpu.flags & mpu.ZERO) # result of AND is zero
self.assertEquals(0x01, mpu.a)
self.assertEquals(0x00, mpu.memory[0x0010 + mpu.x])
# EOR Zero Page, Indirect
def test_eor_zp_indirect_flips_bits_over_setting_z_flag(self):