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FruitMachine-Swift
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cleaning up code

This commit is contained in:
Luigi Thirty 2017-07-25 23:33:26 -04:00
parent 7eb1982c5f
commit fb950c6cec
1 changed files with 37 additions and 185 deletions
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222
FruitMachine/M6502/Opcodes.swift
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@ -103,34 +103,6 @@ func getOperandByteForAddressingMode(state: CPU, mode: AddressingMode) -> UInt8
} }
} }
func getOperandWordForAddressingMode(state: CPU, mode: AddressingMode) -> UInt16 {
//Function that will provide a 16-bit operand to instructions.
//All instructions have 2 data bytes, little-endian.
switch(mode) {
case .absolute:
return state.getOperandWord()
case .absolute_indexed_x:
return state.getOperandWord() + state.index_x
case .absolute_indexed_y:
return state.getOperandWord() + state.index_y
case .indirect:
return state.memoryInterface.readWord(offset: state.getOperandWord())
case .indexed_indirect:
let zp: UInt8 = state.memoryInterface.readByte(offset: UInt16(state.program_counter + 1))
//read from (ZP)
let pointer: UInt16 = state.memoryInterface.readWord(offset: UInt16(zp &+ state.index_x))
return pointer
case .indirect_indexed:
let zp: UInt8 = state.memoryInterface.readByte(offset: UInt16(state.program_counter + 1))
let pointer: UInt16 = state.memoryInterface.readWord(offset: UInt16(zp)) &+ UInt16(state.index_y)
return pointer
default:
print("Called getOperand: UInt16 on an instruction that expects a UInt8. Address: \(state.program_counter.asHexString())")
return 0
}
}
func getOperandAddressForAddressingMode(state: CPU, mode: AddressingMode) -> UInt16 { func getOperandAddressForAddressingMode(state: CPU, mode: AddressingMode) -> UInt16 {
//Function that will provide a 16-bit operand to instructions. //Function that will provide a 16-bit operand to instructions.
//All instructions have 2 data bytes, little-endian. //All instructions have 2 data bytes, little-endian.
@ -139,9 +111,9 @@ func getOperandAddressForAddressingMode(state: CPU, mode: AddressingMode) -> UIn
case .zeropage: case .zeropage:
return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1))) return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1)))
case .zeropage_indexed_x: case .zeropage_indexed_x:
return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1) + state.index_x)) return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1) &+ state.index_x))
case .zeropage_indexed_y: case .zeropage_indexed_y:
return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1) + state.index_y)) return UInt16(0x0000 + (state.memoryInterface.readByte(offset: state.program_counter + 1) &+ state.index_y))
case .absolute: case .absolute:
return state.getOperandWord() return state.getOperandWord()
case .absolute_indexed_x: case .absolute_indexed_x:
@ -157,8 +129,10 @@ func getOperandAddressForAddressingMode(state: CPU, mode: AddressingMode) -> UIn
let zp: UInt8 = state.memoryInterface.readByte(offset: UInt16(state.program_counter + 1)) let zp: UInt8 = state.memoryInterface.readByte(offset: UInt16(state.program_counter + 1))
let pointer: UInt16 = state.memoryInterface.readWord(offset: UInt16(zp)) &+ UInt16(state.index_y) let pointer: UInt16 = state.memoryInterface.readWord(offset: UInt16(zp)) &+ UInt16(state.index_y)
return pointer return pointer
case .indirect:
return state.memoryInterface.readWord(offset: state.getOperandWord())
default: default:
print("Called getOperand: UInt16 on an instruction that expects a UInt8. Address: \(state.program_counter.asHexString())") print("Called getOperandAddressForAddressingMode: UInt16 with an invalid addressing mode. Address: \(state.program_counter.asHexString())")
return 0 return 0
} }
} }
@ -238,71 +212,18 @@ class Opcodes: NSObject {
} }
static func STA(state: CPU, addressingMode: AddressingMode) -> Void { static func STA(state: CPU, addressingMode: AddressingMode) -> Void {
let address: UInt16 let address: UInt16 = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
state.memoryInterface.writeByte(offset: address, value: state.accumulator)
if(addressingMode == .zeropage) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte())
state.memoryInterface.writeByte(offset: address, value: state.accumulator)
}
else if(addressingMode == .zeropage_indexed_x) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte() &+ state.index_x)
state.memoryInterface.writeByte(offset: address, value: state.accumulator)
}
else if (addressingMode == .absolute || addressingMode == .absolute_indexed_x || addressingMode == .absolute_indexed_y) {
address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
state.memoryInterface.writeByte(offset: address, value: state.accumulator)
}
else if(addressingMode == .indexed_indirect || addressingMode == .indirect_indexed) {
address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
state.memoryInterface.writeByte(offset: address, value: state.accumulator)
}
else {
print("Illegal addressing mode for STA")
return
}
} }
static func STX(state: CPU, addressingMode: AddressingMode) -> Void { static func STX(state: CPU, addressingMode: AddressingMode) -> Void {
let address: UInt16 let address: UInt16 = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
state.memoryInterface.writeByte(offset: address, value: state.index_x)
if(addressingMode == .zeropage) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte())
state.memoryInterface.writeByte(offset: address, value: state.index_x)
}
else if(addressingMode == .zeropage_indexed_y) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte() &+ state.index_y)
state.memoryInterface.writeByte(offset: address, value: state.index_x)
}
else if (addressingMode == .absolute) {
address = state.getOperandWord()
state.memoryInterface.writeByte(offset: address, value: state.index_x)
}
else {
print("Illegal addressing mode for STX")
return
}
} }
static func STY(state: CPU, addressingMode: AddressingMode) -> Void { static func STY(state: CPU, addressingMode: AddressingMode) -> Void {
let address: UInt16 let address: UInt16 = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
state.memoryInterface.writeByte(offset: address, value: state.index_y)
if(addressingMode == .zeropage) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte())
state.memoryInterface.writeByte(offset: address, value: state.index_y)
}
else if(addressingMode == .zeropage_indexed_x) {
address = AddressConversions.zeroPageAsUInt16(address: state.getOperandByte() &+ state.index_x)
state.memoryInterface.writeByte(offset: address, value: state.index_y)
}
else if (addressingMode == .absolute) {
address = state.getOperandWord()
state.memoryInterface.writeByte(offset: address, value: state.index_y)
}
else {
print("Illegal addressing mode for STY")
return
}
} }
//Register instructions //Register instructions
@ -363,22 +284,9 @@ class Opcodes: NSObject {
} }
static func INC(state: CPU, addressingMode: AddressingMode) -> Void { static func INC(state: CPU, addressingMode: AddressingMode) -> Void {
let address: UInt16 let address: UInt16 = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var val: UInt8 var val: UInt8 = state.memoryInterface.readByte(offset: address)
if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) {
address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
val = state.memoryInterface.readByte(offset: address)
}
else if (addressingMode == .absolute || addressingMode == .absolute_indexed_x) {
address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
val = state.memoryInterface.readByte(offset: address)
}
else {
print("Illegal addressing mode for INC")
return
}
val = val &+ 1 val = val &+ 1
state.memoryInterface.writeByte(offset: address, value: val) state.memoryInterface.writeByte(offset: address, value: val)
@ -387,21 +295,8 @@ class Opcodes: NSObject {
} }
static func DEC(state: CPU, addressingMode: AddressingMode) -> Void { static func DEC(state: CPU, addressingMode: AddressingMode) -> Void {
let address: UInt16 let address: UInt16 = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var val: UInt8 var val: UInt8 = state.memoryInterface.readByte(offset: address)
if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) {
address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
val = state.memoryInterface.readByte(offset: address)
}
else if (addressingMode == .absolute || addressingMode == .absolute_indexed_x) {
address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
val = state.memoryInterface.readByte(offset: address)
}
else {
print("Illegal addressing mode for DEC")
return
}
val = val &- 1 val = val &- 1
state.memoryInterface.writeByte(offset: address, value: val) state.memoryInterface.writeByte(offset: address, value: val)
@ -415,8 +310,8 @@ class Opcodes: NSObject {
let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode) let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode)
let t = state.accumulator &- mem //CMP is a subtract that doesn't affect memory let t = state.accumulator &- mem //CMP is a subtract that doesn't affect memory
state.status_register.zero = (t == 0) ? true : false state.updateZeroFlag(value: t)
state.status_register.negative = (t & 0x80) == 0x80 ? true : false state.updateNegativeFlag(value: t)
state.status_register.carry = (state.accumulator >= mem) state.status_register.carry = (state.accumulator >= mem)
} }
@ -424,8 +319,8 @@ class Opcodes: NSObject {
let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode) let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode)
let t = state.index_x &- mem //CMP is a subtract that doesn't affect memory let t = state.index_x &- mem //CMP is a subtract that doesn't affect memory
state.status_register.zero = (t == 0) ? true : false state.updateZeroFlag(value: t)
state.status_register.negative = (t & 0x80) == 0x80 ? true : false state.updateNegativeFlag(value: t)
state.status_register.carry = (state.index_x >= mem) state.status_register.carry = (state.index_x >= mem)
} }
@ -433,8 +328,8 @@ class Opcodes: NSObject {
let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode) let mem = getOperandByteForAddressingMode(state: state, mode: addressingMode)
let t = state.index_y &- mem //CMP is a subtract that doesn't affect memory let t = state.index_y &- mem //CMP is a subtract that doesn't affect memory
state.status_register.zero = (t == 0) ? true : false state.updateZeroFlag(value: t)
state.status_register.negative = (t & 0x80) == 0x80 ? true : false state.updateNegativeFlag(value: t)
state.status_register.carry = (state.index_y >= mem) state.status_register.carry = (state.index_y >= mem)
} }
@ -465,8 +360,8 @@ class Opcodes: NSObject {
let operand = getOperandByteForAddressingMode(state: state, mode: addressingMode) let operand = getOperandByteForAddressingMode(state: state, mode: addressingMode)
let data = state.accumulator & operand let data = state.accumulator & operand
state.status_register.zero = data == 0 ? true : false state.updateZeroFlag(value: data)
state.status_register.negative = (operand & 0x80) == 0x80 ? true : false state.updateNegativeFlag(value: operand)
state.status_register.overflow = (operand & UInt8(0x40)) == 0x40 state.status_register.overflow = (operand & UInt8(0x40)) == 0x40
} }
@ -480,7 +375,7 @@ class Opcodes: NSObject {
state.updateZeroFlag(value: state.accumulator) state.updateZeroFlag(value: state.accumulator)
state.updateNegativeFlag(value: state.accumulator) state.updateNegativeFlag(value: state.accumulator)
} }
else if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) else
{ {
let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode) let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address) var data = state.memoryInterface.readByte(offset: address)
@ -490,15 +385,6 @@ class Opcodes: NSObject {
state.updateZeroFlag(value: data) state.updateZeroFlag(value: data)
state.updateNegativeFlag(value: data) state.updateNegativeFlag(value: data)
} }
else {
let address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address)
state.status_register.carry = (data & 0x80) == 0x80
data = (data &<< 1) & 0xFE
state.memoryInterface.writeByte(offset: address, value: data)
state.updateZeroFlag(value: data)
state.updateNegativeFlag(value: data)
}
} }
static func LSR(state: CPU, addressingMode: AddressingMode) -> Void { static func LSR(state: CPU, addressingMode: AddressingMode) -> Void {
@ -508,25 +394,18 @@ class Opcodes: NSObject {
operand = state.accumulator operand = state.accumulator
state.status_register.carry = ((operand & 0x01) == 0x01) state.status_register.carry = ((operand & 0x01) == 0x01)
state.accumulator = (state.accumulator &>> 1) & 0x7F state.accumulator = (state.accumulator &>> 1) & 0x7F
state.updateZeroFlag(value: state.accumulator) state.updateZeroFlag(value: state.accumulator)
state.status_register.negative = false state.updateNegativeFlag(value: state.accumulator)
} }
else if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) else
{ {
let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode) let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address) var data = state.memoryInterface.readByte(offset: address)
state.status_register.carry = (data & 0x01) == 0x01 state.status_register.carry = (data & 0x01) == 0x01
data = (data &>> 1) & 0x7F data = (data &>> 1) & 0x7F
state.memoryInterface.writeByte(offset: address, value: data) state.memoryInterface.writeByte(offset: address, value: data)
state.updateZeroFlag(value: data)
state.updateNegativeFlag(value: data)
}
else {
let address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address)
state.status_register.carry = (data & 0x01) == 0x01
data = (data &>> 1) & 0x7F
state.memoryInterface.writeByte(offset: address, value: data)
state.updateZeroFlag(value: data) state.updateZeroFlag(value: data)
state.updateNegativeFlag(value: data) state.updateNegativeFlag(value: data)
} }
@ -544,7 +423,8 @@ class Opcodes: NSObject {
state.status_register.carry = ((operand & 0x80) == 0x80) state.status_register.carry = ((operand & 0x80) == 0x80)
state.status_register.zero = state.accumulator == 0 ? true : false state.status_register.zero = state.accumulator == 0 ? true : false
state.status_register.negative = (state.accumulator & 0x80) == 0x80 state.status_register.negative = (state.accumulator & 0x80) == 0x80
} else if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) }
else
{ {
let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode) let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address) var data = state.memoryInterface.readByte(offset: address)
@ -555,22 +435,8 @@ class Opcodes: NSObject {
state.memoryInterface.writeByte(offset: address, value: data) state.memoryInterface.writeByte(offset: address, value: data)
state.status_register.carry = t state.status_register.carry = t
state.status_register.zero = data == 0 ? true : false state.updateZeroFlag(value: data)
state.status_register.negative = (data & 0x80) == 0x80 state.updateNegativeFlag(value: data)
}
else
{
let address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address)
let t = (data & 0x80) == 0x80 ? true : false
data = (data &<< 1) & 0xFE
data = data | (state.status_register.carry ? 0x01 : 0x00)
state.memoryInterface.writeByte(offset: address, value: data)
state.status_register.carry = t
state.status_register.zero = data == 0 ? true : false
state.status_register.negative = (data & 0x80) == 0x80
} }
} }
@ -587,7 +453,7 @@ class Opcodes: NSObject {
state.status_register.zero = state.accumulator == 0 ? true : false state.status_register.zero = state.accumulator == 0 ? true : false
state.status_register.negative = (state.accumulator & 0x80) == 0x80 state.status_register.negative = (state.accumulator & 0x80) == 0x80
} }
else if(addressingMode == .zeropage || addressingMode == .zeropage_indexed_x) else
{ {
let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode) let address = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address) var data = state.memoryInterface.readByte(offset: address)
@ -598,22 +464,8 @@ class Opcodes: NSObject {
state.memoryInterface.writeByte(offset: address, value: data) state.memoryInterface.writeByte(offset: address, value: data)
state.status_register.carry = t state.status_register.carry = t
state.status_register.zero = data == 0 ? true : false state.updateZeroFlag(value: data)
state.status_register.negative = (data & 0x80) == 0x80 state.updateNegativeFlag(value: data)
}
else
{
let address = getOperandWordForAddressingMode(state: state, mode: addressingMode)
var data = state.memoryInterface.readByte(offset: address)
let t = (data & 0x01) == 0x01 ? true : false
data = (data &>> 1) & 0x7F
data = data | (state.status_register.carry ? 0x80 : 0x00)
state.memoryInterface.writeByte(offset: address, value: data)
state.status_register.carry = t
state.status_register.zero = data == 0 ? true : false
state.status_register.negative = (data & 0x80) == 0x80
} }
} }
@ -734,7 +586,7 @@ class Opcodes: NSObject {
//Misc //Misc
static func JMP(state: CPU, addressingMode: AddressingMode) -> Void { static func JMP(state: CPU, addressingMode: AddressingMode) -> Void {
state.program_counter = getOperandWordForAddressingMode(state: state, mode: addressingMode) state.program_counter = getOperandAddressForAddressingMode(state: state, mode: addressingMode)
} }
static func JSR(state: CPU, addressingMode: AddressingMode) -> Void { static func JSR(state: CPU, addressingMode: AddressingMode) -> Void {