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Code Issues Projects Releases Wiki Activity

Fixes failing tests

This commit is contained in:
Felipe Lima 2015-06-16 23:20:23 -07:00
parent 908f42587b
commit 4f9f9c4b9b
12 changed files with 137 additions and 46 deletions
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105
app/src/main/kotlin/android/emu6502/CPU.kt
View File

@ -8,7 +8,7 @@ import android.util.Log
import java.util.HashMap
import kotlin.reflect.KMemberFunction0
class CPU(private val memory: Memory) {
class CPU(val memory: Memory) {
// Accumulator
var A: Int = 0
// Registers
@ -19,7 +19,7 @@ class CPU(private val memory: Memory) {
// Stack pointer
var SP: Int = 0xFF
// Processor flags
var P: Int = 0
var P: Int = 0x30
private var isRunning = false
private var debug = false
private var monitoring = false
@ -37,18 +37,19 @@ class CPU(private val memory: Memory) {
Pair(Instruction.STX, STX(this)),
Pair(Instruction.TAX, TAX(this)),
Pair(Instruction.INX, INX(this)),
Pair(Instruction.ORA, ORA(this))
Pair(Instruction.DEX, DEX(this)),
Pair(Instruction.ORA, ORA(this)),
Pair(Instruction.CPX, CPX(this)),
Pair(Instruction.BRK, BRK(this)),
Pair(Instruction.BNE, BNE(this))
// Pair(Instruction.BPL, BPL(this)),
// Pair(Instruction.BMI, BMI(this)),
// Pair(Instruction.BVC, BVC(this)),
// Pair(Instruction.BVS, BVS(this)),
// Pair(Instruction.BCC, BCC(this)),
// Pair(Instruction.BCS, BCS(this)),
// Pair(Instruction.BNE, BNE(this)),
// Pair(Instruction.BEQ, BEQ(this)),
// Pair(Instruction.BRK, BRK(this)),
// Pair(Instruction.CMP, CMP(this)),
// Pair(Instruction.CPX, CPX(this)),
// Pair(Instruction.CPY, CPY(this)),
// Pair(Instruction.DEC, DEC(this)),
// Pair(Instruction.EOR, EOR(this)),
@ -65,7 +66,6 @@ class CPU(private val memory: Memory) {
// Pair(Instruction.LSR, LSR(this)),
// Pair(Instruction.NOP, NOP(this)),
// Pair(Instruction.TXA, TXA(this)),
// Pair(Instruction.DEX, DEX(this)),
// Pair(Instruction.TAY, TAY(this)),
// Pair(Instruction.TYA, TYA(this)),
// Pair(Instruction.DEY, DEY(this)),
@ -124,14 +124,14 @@ class CPU(private val memory: Memory) {
}
fun setSZFlagsForRegA() {
setSZFlagsForValue(A)
setSVFlagsForValue(A)
}
fun setSZflagsForRegX() {
setSZFlagsForValue(X)
setSVFlagsForValue(X)
}
private fun setSZFlagsForValue(value: Int) {
private fun setSVFlagsForValue(value: Int) {
if (value != 0) {
P = P.and(0xfd)
} else {
@ -156,34 +156,34 @@ class CPU(private val memory: Memory) {
setOverflow()
}
if (decimalMode().isSet()) {
tmp = A.and(0xf) + value.and(0xf) + carry()
if (decimalMode()) {
tmp = A.and(0xf) + value.and(0xf) + P.and(1)
if (tmp >= 10) {
tmp = 0x10.or((tmp + 6).and(0xf))
}
tmp += A.and(0xf0) + value.and(0xf0)
if (tmp >= 160) {
SEC()
if (overflow().isSet() && tmp >= 0x180) {
if (overflow() && tmp >= 0x180) {
CLV()
}
tmp += 0x60
} else {
CLC()
if (overflow().isSet() && tmp < 0x80) {
if (overflow() && tmp < 0x80) {
CLV()
}
}
} else {
tmp = A + value + carry()
tmp = A + value + P.and(1)
if (tmp >= 0x100) {
SEC()
if (overflow().isSet() && tmp >= 0x180) {
if (overflow() && tmp >= 0x180) {
CLV()
}
} else {
CLC()
if (overflow().isSet() && tmp < 0x80) {
if (overflow() && tmp < 0x80) {
CLV()
}
}
@ -192,42 +192,85 @@ class CPU(private val memory: Memory) {
setSZFlagsForRegA()
}
fun overflow(): Int {
return P.and(0x40)
private fun overflow(): Boolean {
return P.and(0x40) != 0
}
fun decimalMode(): Int {
return P.and(8);
private fun decimalMode(): Boolean {
return P.and(8) != 0
}
fun carry(): Int {
return P.and(1);
private fun carry(): Boolean {
return P.and(1) != 0
}
fun negative(): Int {
return P.and(0x80);
private fun negative(): Boolean {
return P.and(0x80) != 0
}
fun zero(): Int {
return P.and(0x02);
fun zero(): Boolean {
return P.and(0x02) != 0
}
fun jumpBranch(offset: Int) {
if (offset > 0x7f) {
PC -= (0x100 - offset)
} else {
PC += offset
}
}
fun doCompare(reg: Int, value: Int) {
if (reg >= value) {
SEC()
} else {
CLC()
}
setSVFlagsForValue(reg - value)
}
/** CLear Carry */
fun CLC() {
private fun CLC() {
P = P.and(0xfe)
}
/** SEt Carry */
fun SEC() {
private fun SEC() {
P = P.or(1)
}
/** CLear oVerflow */
fun CLV() {
private fun CLV() {
P = P.and(0xbf)
}
fun setOverflow() {
private fun setOverflow() {
P = P.or(0x40)
}
/**
* http://nesdev.com/6502.txt
* Returns the processor flags in the format SV-BDIZC
* Sign - this is set if the result of an operation is negative, cleared if positive.
* Overflow - when an arithmetic operation produces a result too large to be represented in a byte
* Unused - Supposed to be logical 1 at all times.
* Break - this is set when a software interrupt (BRK instruction) is executed.
* Decimal Mode - When set, and an Add with Carry or Subtract with Carry instruction is executed,
* the source values are treated as valid BCD (Binary Coded Decimal, eg. 0x00-0x99 = 0-99) numbers.
* The result generated is also a BCD number.
* Interrupt - If it is set, interrupts are disabled. If it is cleared, interrupts are enabled.
* Zero - this is set to 1 when any arithmetic or logical operation produces a zero result, and is
* set to 0 if the result is non-zero.
* Carry - this holds the carry out of the most significant bit in any arithmetic operation.
* In subtraction operations however, this flag is cleared - set to 0 - if a borrow is required,
* set to 1 - if no borrow is required. The carry flag is also used in shift and rotate logical
* operations.
* */
fun flags(): String {
val flags = StringBuilder()
for (i in 7 downTo 0) {
flags.append(P.shr(i).and(1))
}
return flags.toString()
}
}

4
app/src/main/kotlin/android/emu6502/Utils.kt
View File

@ -2,8 +2,4 @@ package android.emu6502
fun Int.toHexString(): String {
return java.lang.String.format("%02X", this);
}
fun Int.isSet(): Boolean {
return this != 0
}

15
app/src/main/kotlin/android/emu6502/instructions/impl/BNE.kt Normal file
View File

@ -0,0 +1,15 @@
package android.emu6502.instructions.impl
import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** Branch on Not Equal */
final class BNE(private val cpu: CPU) : BaseInstruction(Instruction.BNE, cpu.instructionList) {
override fun branch() {
val offset = cpu.popByte()
if (!cpu.zero()) {
cpu.jumpBranch(offset)
}
}
}

2
app/src/main/kotlin/android/emu6502/instructions/impl/BRK.kt
View File

@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** BRreaK */
final class BRK(private val cpu: CPU) : BaseInstruction(Instruction.INX, cpu.instructionList) {
final class BRK(private val cpu: CPU) : BaseInstruction(Instruction.BRK, cpu.instructionList) {
override fun single() {
cpu.stop()
}

13
app/src/main/kotlin/android/emu6502/instructions/impl/CPX.kt Normal file
View File

@ -0,0 +1,13 @@
package android.emu6502.instructions.impl
import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** ComPare X register */
class CPX(private val cpu: CPU) : BaseInstruction(Instruction.CPX, cpu.instructionList) {
override fun immediate() {
val value = cpu.popByte()
cpu.doCompare(cpu.X, value)
}
}

14
app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt Normal file
View File

@ -0,0 +1,14 @@
package android.emu6502.instructions.impl
import android.emu6502.CPU
import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/**DEcrement X */
class DEX(private val cpu: CPU) : BaseInstruction(Instruction.DEX, cpu.instructionList) {
override fun single() {
cpu.X = (cpu.X - 1).and(0xff)
cpu.setSZflagsForRegX()
}
}

4
app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt
View File

@ -5,9 +5,7 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** LoaD Accumulator */
class LDA(private val cpu: CPU)
: BaseInstruction(Instruction.LDA, cpu.instructionList) {
class LDA(private val cpu: CPU) : BaseInstruction(Instruction.LDA, cpu.instructionList) {
override fun immediate() {
cpu.A = cpu.popByte()
cpu.setSZFlagsForRegA()

6
app/src/main/kotlin/android/emu6502/instructions/impl/LDX.kt
View File

@ -5,5 +5,9 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** LoaD X register */
class LDX(cpu: CPU) : BaseInstruction(Instruction.LDX, cpu.instructionList) {
class LDX(private val cpu: CPU) : BaseInstruction(Instruction.LDX, cpu.instructionList) {
override fun immediate() {
cpu.X = cpu.popByte()
cpu.setSZflagsForRegX()
}
}

3
app/src/main/kotlin/android/emu6502/instructions/impl/LDY.kt
View File

@ -5,6 +5,5 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** LoaD Y register */
class LDY(cpu: CPU)
: BaseInstruction(Instruction.LDY, cpu.instructionList) {
class LDY(cpu: CPU) : BaseInstruction(Instruction.LDY, cpu.instructionList) {
}

3
app/src/main/kotlin/android/emu6502/instructions/impl/ORA.kt
View File

@ -5,6 +5,5 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** bitwise OR with Accumulator */
class ORA(cpu: CPU)
: BaseInstruction(Instruction.ORA, cpu.instructionList) {
class ORA(cpu: CPU) : BaseInstruction(Instruction.ORA, cpu.instructionList) {
}

10
app/src/main/kotlin/android/emu6502/instructions/impl/STX.kt
View File

@ -5,6 +5,12 @@ import android.emu6502.instructions.BaseInstruction
import android.emu6502.instructions.Instruction
/** STore X register */
class STX(cpu: CPU)
: BaseInstruction(Instruction.STX, cpu.instructionList) {
class STX(private val cpu: CPU) : BaseInstruction(Instruction.STX, cpu.instructionList) {
override fun zeroPage() {
cpu.memory.storeByte(cpu.popByte(), cpu.X)
}
override fun absolute() {
cpu.memory.storeByte(cpu.popWord(), cpu.X)
}
}

4
app/src/test/java/android/emu6502/CPUTest.java
View File

@ -38,6 +38,7 @@ public class CPUTest {
assertThat(cpu.getY(), equalTo(0x00));
assertThat(cpu.getSP(), equalTo(0xFF));
assertThat(cpu.getPC(), equalTo(0x0610));
assertThat(cpu.flags(), equalTo("00110000"));
}
@Test public void testWithComments() {
@ -54,6 +55,7 @@ public class CPUTest {
assertThat(cpu.getY(), equalTo(0x00));
assertThat(cpu.getSP(), equalTo(0xFF));
assertThat(cpu.getPC(), equalTo(0x0607));
assertThat(cpu.flags(), equalTo("10110001"));
}
@Test public void testBranchAndLabel() {
@ -67,10 +69,12 @@ public class CPUTest {
"STX $0201",
"BRK");
assembler.assembleCode(lines);
cpu.execute();
assertThat(cpu.getA(), equalTo(0x00));
assertThat(cpu.getX(), equalTo(0x03));
assertThat(cpu.getY(), equalTo(0x00));
assertThat(cpu.getSP(), equalTo(0xFF));
assertThat(cpu.getPC(), equalTo(0x060e));
assertThat(cpu.flags(), equalTo("00110011"));
}
}