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Found and fixed some timing errors in absolute indexed and in (indirect), y addressing modes: neither is able in write or read-modify-write modes to shave a cycle as then can when reading.

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This commit is contained in:
Thomas Harte 2015-08-13 02:58:39 +01:00
parent 975836c30f
commit dd0f17130a
2 changed files with 59 additions and 10 deletions
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41
OSBindings/Mac/Clock SignalTests/TimingTests.swift
View File

@ -13,9 +13,9 @@ class TimingTests: XCTestCase, CSTestMachineJamHandler {
private var endTime: UInt32 = 0
func testImpliedNOP() {
let code: [UInt8] = [0xea, CSTestMachineJamOpcode]
self.runTest(code, expectedRunLength: 2)
func testImplied() {
let code: [UInt8] = [0xea, 0x88, 0xca, CSTestMachineJamOpcode]
self.runTest(code, expectedRunLength: 6)
}
func testLDA() {
@ -35,6 +35,33 @@ class TimingTests: XCTestCase, CSTestMachineJamHandler {
self.runTest(code, expectedRunLength: 48)
}
func testSTA() {
let code: [UInt8] = [
0x85, 0x00, // [3] STA $00
0x95, 0x00, // [4] STA $00,X
0x8d, 0x00, 0x00, // [4] STA $0000
0x9d, 0x00, 0x00, // [5] STA $0000, x (no wrap)
0x9d, 0x02, 0x00, // [5] STA $0002, x (wrap)
0x99, 0x00, 0x00, // [5] STA $0000, y (no wrap)
0x99, 0x10, 0x00, // [5] STA $0010, y (wrap)
0x81, 0x44, // [6] STA ($44, x)
0x91, 0x00, // [6] STA ($00), y (no wrap)
0x91, 0x02, // [6] STA ($01), y (wrap)
CSTestMachineJamOpcode]
self.runTest(code, expectedRunLength: 49)
}
func testINC() {
let code: [UInt8] = [
0xe6, 0x00, // [5] INC $00
0xf6, 0x00, // [6] INC $00,X
0xee, 0x00, 0x00, // [6] INC $0000
0xfe, 0x00, 0x00, // [7] INC $0000, x (no wrap)
0xfe, 0x02, 0x00, // [7] INC $0002, x (wrap)
CSTestMachineJamOpcode]
self.runTest(code, expectedRunLength: 31)
}
func testBCS() {
let code: [UInt8] = [
0x18, // [2] CLC
@ -70,6 +97,14 @@ class TimingTests: XCTestCase, CSTestMachineJamHandler {
self.runTest(code, expectedRunLength: 9)
}
func testSnippet2() {
let code: [UInt8] = [
0x16, 0x16, // [6] ASL $16, x
0x46, 0x46, // [5] LSR $46
CSTestMachineJamOpcode]
self.runTest(code, expectedRunLength: 11)
}
func runTest(code: [UInt8], expectedRunLength: UInt32) {
let machine = CSTestMachine()

28
Processors/6502/CPU6502.hpp
View File

@ -63,7 +63,8 @@ template <class T> class Processor {
CycleReadAndIncrementPC, CycleIncrementPCAndReadStack, CycleIncrementPCReadPCHLoadPCL, CycleReadPCHLoadPCL,
CycleReadAddressHLoadAddressL, CycleReadPCLFromAddress, CycleReadPCHFromAddress, CycleLoadAddressAbsolute,
OperationLoadAddressZeroPage, CycleLoadAddessZeroX, CycleLoadAddessZeroY, CycleAddXToAddressLow,
CycleAddYToAddressLow, OperationCorrectAddressHigh, OperationMoveToNextProgram, OperationIncrementPC,
CycleAddYToAddressLow, CycleAddXToAddressLowRead, OperationCorrectAddressHigh, CycleAddYToAddressLowRead,
OperationMoveToNextProgram, OperationIncrementPC,
CycleFetchOperandFromAddress, CycleWriteOperandToAddress, OperationCopyOperandFromA, OperationCopyOperandToA,
CycleIncrementPCFetchAddressLowFromOperand, CycleAddXToOperandFetchAddressLow, CycleIncrementOperandFetchAddressHigh, OperationDecrementOperand,
OperationIncrementOperand, OperationORA, OperationAND, OperationEOR,
@ -137,26 +138,29 @@ template <class T> class Processor {
#define Program(...) {__VA_ARGS__, OperationMoveToNextProgram}
#define Absolute CycleLoadAddressAbsolute
#define AbsoluteX CycleLoadAddressAbsolute, CycleAddXToAddressLow, OperationCorrectAddressHigh
#define AbsoluteY CycleLoadAddressAbsolute, CycleAddYToAddressLow, OperationCorrectAddressHigh
#define AbsoluteXr CycleLoadAddressAbsolute, CycleAddXToAddressLow, OperationCorrectAddressHigh
#define AbsoluteYr CycleLoadAddressAbsolute, CycleAddYToAddressLow, OperationCorrectAddressHigh
#define AbsoluteX CycleLoadAddressAbsolute, CycleAddXToAddressLowRead, OperationCorrectAddressHigh
#define AbsoluteY CycleLoadAddressAbsolute, CycleAddYToAddressLowRead, OperationCorrectAddressHigh
#define Zero OperationLoadAddressZeroPage
#define ZeroX CycleLoadAddessZeroX
#define ZeroY CycleLoadAddessZeroY
#define IndexedIndirect CycleIncrementPCFetchAddressLowFromOperand, CycleAddXToOperandFetchAddressLow, CycleIncrementOperandFetchAddressHigh
#define IndirectIndexed CycleIncrementPCFetchAddressLowFromOperand, CycleIncrementOperandFetchAddressHigh, CycleAddYToAddressLow, OperationCorrectAddressHigh
#define IndirectIndexedr CycleIncrementPCFetchAddressLowFromOperand, CycleIncrementOperandFetchAddressHigh, CycleAddYToAddressLow, OperationCorrectAddressHigh
#define IndirectIndexed CycleIncrementPCFetchAddressLowFromOperand, CycleIncrementOperandFetchAddressHigh, CycleAddYToAddressLowRead, OperationCorrectAddressHigh
#define Read(op) CycleFetchOperandFromAddress, op
#define Write(op) op, CycleWriteOperandToAddress
#define ReadModifyWrite(...) CycleFetchOperandFromAddress, CycleWriteOperandToAddress, __VA_ARGS__, CycleWriteOperandToAddress
#define AbsoluteRead(op) Program(Absolute, Read(op))
#define AbsoluteXRead(op) Program(AbsoluteX, Read(op))
#define AbsoluteYRead(op) Program(AbsoluteY, Read(op))
#define AbsoluteXRead(op) Program(AbsoluteXr, Read(op))
#define AbsoluteYRead(op) Program(AbsoluteYr, Read(op))
#define ZeroRead(op) Program(Zero, Read(op))
#define ZeroXRead(op) Program(ZeroX, Read(op))
#define ZeroYRead(op) Program(ZeroY, Read(op))
#define IndexedIndirectRead(op) Program(IndexedIndirect, Read(op))
#define IndirectIndexedRead(op) Program(IndirectIndexed, Read(op))
#define IndirectIndexedRead(op) Program(IndirectIndexedr, Read(op))
#define AbsoluteWrite(op) Program(Absolute, Write(op))
#define AbsoluteXWrite(op) Program(AbsoluteX, Write(op))
@ -745,6 +749,11 @@ template <class T> class Processor {
throwaway_read(_address.full);
}
break;
case CycleAddXToAddressLowRead:
_nextAddress.full = _address.full + _x;
_address.bytes.low = _nextAddress.bytes.low;
throwaway_read(_address.full);
break;
case CycleAddYToAddressLow:
_nextAddress.full = _address.full + _y;
_address.bytes.low = _nextAddress.bytes.low;
@ -752,6 +761,11 @@ template <class T> class Processor {
throwaway_read(_address.full);
}
break;
case CycleAddYToAddressLowRead:
_nextAddress.full = _address.full + _y;
_address.bytes.low = _nextAddress.bytes.low;
throwaway_read(_address.full);
break;
case OperationCorrectAddressHigh:
_address.full = _nextAddress.full;
break;