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Removed duplication in instructions using immediate mode.

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This commit is contained in:
Mike Naberezny 2009-08-07 22:27:26 -07:00
parent ccf950019f
commit 421eac9233
1 changed files with 26 additions and 84 deletions
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88
src/py65/devices/mpu6502.py
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@ -69,6 +69,9 @@ class MPU:
def WordAt(self, addr):
return self.ByteAt(addr) + (self.ByteAt(addr + 1) << 8)
def ProgramCounter(self):
return self.pc
# Addressing modes
def ImmediateByte(self):
@ -248,10 +251,7 @@ class MPU:
self.FlagsNZ(self.a)
def opADC(self, x):
if callable(x):
data = self.ByteAt(x())
else:
data = x
if self.flags & self.DECIMAL:
if self.flags & self.CARRY:
@ -342,6 +342,7 @@ class MPU:
def opSBC(self, x):
data = self.ByteAt(x())
if self.flags & self.DECIMAL:
if self.flags & self.CARRY:
borrow = 0
@ -456,8 +457,7 @@ class MPU:
@instruction(name="ORA", mode="imm", cycles=2)
def inst_0x09(self):
self.a |= self.ImmediateByte()
self.FlagsNZ(self.a)
self.opORA(self.ProgramCounter)
self.pc += 1
@instruction(name="ASL", mode="acc", cycles=2)
@ -549,8 +549,7 @@ class MPU:
@instruction(name="AND", mode="imm", cycles=2)
def inst_0x29(self):
self.a &= self.ImmediateByte()
self.FlagsNZ(self.a)
self.opAND(self.ProgramCounter)
self.pc += 1
@instruction(name="ROL", mode="acc", cycles=2)
@ -645,8 +644,7 @@ class MPU:
@instruction(name="EOR", mode="imm", cycles=2)
def inst_0x49(self):
self.a ^= self.ImmediateByte()
self.FlagsNZ(self.a)
self.opEOR(self.ProgramCounter)
self.pc += 1
@instruction(name="LSR", mode="acc", cycles=2)
@ -741,7 +739,7 @@ class MPU:
@instruction(name="ADC", mode="imm", cycles=2)
def inst_0x69(self):
self.opADC(self.ImmediateByte())
self.opADC(self.ProgramCounter)
self.pc += 1
@instruction(name="ROR", mode="acc", cycles=2)
@ -901,8 +899,7 @@ class MPU:
@instruction(name="LDY", mode="imm", cycles=2)
def inst_0xa0(self):
self.y=self.ImmediateByte()
self.FlagsNZ(self.y)
self.opLDY(self.ProgramCounter)
self.pc += 1
@instruction(name="LDA", mode="inx", cycles=6)
@ -912,8 +909,7 @@ class MPU:
@instruction(name="LDX", mode="imm", cycles=2)
def inst_0xa2(self):
self.x=self.ImmediateByte()
self.FlagsNZ(self.x)
self.opLDX(self.ProgramCounter)
self.pc += 1
@instruction(name="LDY", mode="zpg", cycles=3)
@ -938,8 +934,7 @@ class MPU:
@instruction(name="LDA", mode="imm", cycles=2)
def inst_0xa9(self):
self.a = self.ImmediateByte()
self.FlagsNZ(self.a)
self.opLDA(self.ProgramCounter)
self.pc += 1
@instruction(name="TAX", mode="imp", cycles=2)
@ -1017,14 +1012,7 @@ class MPU:
@instruction(name="CPY", mode="imm", cycles=2)
def inst_0xc0(self):
tbyte = self.ImmediateByte()
self.flags &= ~(self.CARRY+self.ZERO+self.NEGATIVE)
if self.y == tbyte:
self.flags |= self.CARRY+self.ZERO
elif self.y > tbyte:
self.flags |= self.CARRY
else:
self.flags |= self.NEGATIVE
self.opCPY(self.ProgramCounter)
self.pc += 1
@instruction(name="CMP", mode="inx", cycles=6)
@ -1055,14 +1043,7 @@ class MPU:
@instruction(name="CMP", mode="imm", cycles=2)
def inst_0xc9(self):
tbyte = self.ImmediateByte()
self.flags &= ~(self.CARRY+self.ZERO+self.NEGATIVE)
if self.a == tbyte:
self.flags |= self.CARRY + self.ZERO
elif self.a > tbyte:
self.flags |= self.CARRY
else:
self.flags |= self.NEGATIVE
self.opCMP(self.ProgramCounter)
self.pc +=1
@instruction(name="DEX", mode="imp", cycles=2)
@ -1126,14 +1107,7 @@ class MPU:
@instruction(name="CPX", mode="imm", cycles=2)
def inst_0xe0(self):
tbyte = self.ImmediateByte()
self.flags &= ~(self.CARRY+self.ZERO+self.NEGATIVE)
if self.x == tbyte:
self.flags |= self.CARRY + self.ZERO
elif self.x > tbyte:
self.flags |= self.CARRY
else:
self.flags |= self.NEGATIVE
self.opCPX(self.ProgramCounter)
self.pc += 1
@instruction(name="SBC", mode="inx", cycles=6)
@ -1164,39 +1138,7 @@ class MPU:
@instruction(name="SBC", mode="imm", cycles=2)
def inst_0xe9(self):
data=self.ImmediateByte()
if self.flags & self.DECIMAL:
if self.flags & self.CARRY:
tmp = 0
else:
tmp = 1
data = convert_to_bin(self.a) - convert_to_bin(data) - tmp
self.flags &= ~(self.CARRY+self.ZERO+self.NEGATIVE+self.OVERFLOW)
if data == 0:
self.flags |= self.ZERO + self.CARRY
elif data > 0:
self.flags |= self.CARRY
else:
self.flags |= self.NEGATIVE
data +=100
self.a = convert_to_bcd(data)
else:
if self.flags & self.CARRY:
tmp = 0
else:
tmp = 1
data = self.a - data - tmp
self.flags &= ~(self.CARRY+self.ZERO+self.OVERFLOW+self.NEGATIVE)
if data == 0:
self.flags |= self.ZERO + self.CARRY
elif data > 0:
self.flags |= self.CARRY
else:
self.flags |= self.OVERFLOW
data &= 255
self.flags |= data & 128
self.a = data
self.opSBC(self.ProgramCounter)
self.pc += 1
@instruction(name="NOP", mode="imp", cycles=2)