package com.loomcom.symon;
import com.loomcom.symon.devices.Memory;
import com.loomcom.symon.exceptions.MemoryAccessException;
import junit.framework.TestCase;
public class CpuAbsoluteYModeTest extends TestCase {
protected Cpu cpu;
protected Bus bus;
protected Memory mem;
protected void setUp() throws Exception {
this.cpu = new Cpu();
this.bus = new Bus(0x0000, 0xffff);
this.mem = new Memory(0x0000, 0xffff);
bus.addCpu(cpu);
bus.addDevice(mem);
// Load the reset vector.
bus.write(0xfffc, Bus.DEFAULT_LOAD_ADDRESS & 0x00ff);
bus.write(0xfffd, (Bus.DEFAULT_LOAD_ADDRESS & 0xff00) >>> 8);
cpu.reset();
// Assert initial state
assertEquals(0, cpu.getAccumulator());
assertEquals(0, cpu.getXRegister());
assertEquals(0, cpu.getYRegister());
assertEquals(0x200, cpu.getProgramCounter());
assertEquals(0xff, cpu.getStackPointer());
assertEquals(0x20, cpu.getProcessorStatus());
}
/*
* The following opcodes are tested for correctness in this file:
*
* ORA - $19
* AND - $39
* EOR - $59
* ADC - $79
* STA - $99
* LDA - $b9
* LDX - $be
* CMP - $d9
* SBC - $f9
*/
/* ORA - Logical Inclusive OR - $19 */
public void test_ORA() throws MemoryAccessException {
// Set some initial values in memory
bus.write(0x2c30, 0x00);
bus.write(0x2c32, 0x11);
bus.write(0x2c34, 0x22);
bus.write(0x2c38, 0x44);
bus.write(0x2c40, 0x88);
// Set offset in Y register.
cpu.setYRegister(0x30);
bus.loadProgram(0x19, 0x00, 0x2c, // ORA $2c00,Y
0x19, 0x02, 0x2c, // ORA $2c02,Y
0x19, 0x04, 0x2c, // ORA $2c04,Y
0x19, 0x08, 0x2c, // ORA $2c08,Y
0x19, 0x10, 0x2c); // ORA $2c10,Y
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x11, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x33, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x77, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0xff, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* AND - Logical AND - $39 */
public void test_AND() throws MemoryAccessException {
bus.write(0x1a30, 0x00);
bus.write(0x1a31, 0x11);
bus.write(0x1a32, 0xff);
bus.write(0x1a33, 0x99);
bus.write(0x1a34, 0x11);
bus.write(0x1a35, 0x0f);
bus.write(0x1a02, 0x11);
// Set offset in Y register.
cpu.setYRegister(0x30);
bus.loadProgram(0x39, 0x00, 0x1a, // AND $1a00,Y
0x39, 0x01, 0x1a, // AND $1a01,Y
0xa9, 0xaa, // LDA #$aa
0x39, 0x02, 0x1a, // AND $1a02,Y
0x39, 0x03, 0x1a, // AND $1a03,Y
0x39, 0x04, 0x1a, // AND $1a04,Y
0xa9, 0xff, // LDA #$ff
0x39, 0x05, 0x1a, // AND $1a05,Y
0xa9, 0x01, // LDA #$01
0x39, 0xd2, 0x19); // AND $19d2,Y
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step(2);
assertEquals(0xaa, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x88, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step(2);
assertEquals(0x0f, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step(2);
assertEquals(0x01, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
}
/* EOR - Exclusive OR - $59 */
public void test_EOR() throws MemoryAccessException {
bus.write(0xab40, 0x00);
bus.write(0xab41, 0xff);
bus.write(0xab42, 0x33);
bus.write(0xab43, 0x44);
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x88, // LDA #$88
0x59, 0x10, 0xab, // EOR $ab10,Y
0x59, 0x11, 0xab, // EOR $ab11,Y
0x59, 0x12, 0xab, // EOR $ab12,Y
0x59, 0x13, 0xab); // EOR $ab13,Y
cpu.step(2);
assertEquals(0x88, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getZeroFlag());
cpu.step();
assertEquals(0x77, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getZeroFlag());
cpu.step();
assertEquals(0x44, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getZeroFlag());
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getZeroFlag());
}
/* ADC - Add with Carry - $79 */
public void test_ADC() throws MemoryAccessException {
bus.write(0xab40, 0x01);
bus.write(0xab41, 0xff);
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(2);
assertEquals(0x01, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x7f, // LDA #$7f
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(2);
assertEquals(0x80, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x80, // LDA #$80
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(2);
assertEquals(0x81, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(2);
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(2);
assertEquals(0xff, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x7f, // LDA #$7f
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(2);
assertEquals(0x7e, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0x80, // LDA #$80
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(2);
assertEquals(0x7f, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(2);
assertEquals(0xfe, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
}
public void test_ADC_IncludesCarry() throws MemoryAccessException {
bus.write(0xab40, 0x01);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x38, // SEC
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x02, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
}
public void test_ADC_DecimalMode() throws MemoryAccessException {
bus.write(0xab40, 0x01);
bus.write(0xab41, 0x99);
bus.loadProgram(0xf8, // SED
0xa9, 0x01, // LDA #$01
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x02, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x49, // LDA #$49
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(3);
assertEquals(0x50, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x50, // LDA #$50
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(3);
assertEquals(0x51, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x99, // LDA #$99
0x79, 0x10, 0xab); // ADC $ab10,Y
cpu.step(3);
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x00, // LDA #$00
0x79, 0x11, 0xab); // ADC $ab10,Y
cpu.step(3);
assertEquals(0x99, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x49, // LDA #$49
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(3);
assertEquals(0x48, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setYRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x50, // LDA #$59
0x79, 0x11, 0xab); // ADC $ab11,Y
cpu.step(3);
assertEquals(0x49, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
}
/* STA - Store Accumulator - $99 */
public void test_STA() throws MemoryAccessException {
cpu.setYRegister(0x30);
cpu.setAccumulator(0x00);
bus.loadProgram(0x99, 0x10, 0xab); // STA $ab10,Y
cpu.step();
assertEquals(0x00, bus.read(0xab40));
// STA should have NO effect on flags
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setYRegister(0x30);
cpu.setAccumulator(0x0f);
bus.loadProgram(0x99, 0x10, 0xab); // STA $ab10,Y
cpu.step();
assertEquals(0x0f, bus.read(0xab40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setYRegister(0x30);
cpu.setAccumulator(0x80);
bus.loadProgram(0x99, 0x10, 0xab); // STA $ab10,Y
cpu.step();
assertEquals(0x80, bus.read(0xab40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
}
/* LDX - Load X Register - $be */
public void test_LDX() throws MemoryAccessException {
bus.write(0xab45, 0x00);
bus.write(0xab46, 0x0f);
bus.write(0xab47, 0x80);
bus.loadProgram(0xbe, 0x10, 0xab, // LDX $ab10,Y
0xbe, 0x11, 0xab, // LDX $ab11,Y
0xbe, 0x12, 0xab); // LDX $ab12,Y
cpu.setYRegister(0x35);
cpu.step();
assertEquals(0x00, cpu.getXRegister());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x0f, cpu.getXRegister());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x80, cpu.getXRegister());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* LDA - Load Accumulator - $b9 */
public void test_LDA() throws MemoryAccessException {
bus.write(0xab42, 0x00);
bus.write(0xab43, 0x0f);
bus.write(0xab44, 0x80);
bus.loadProgram(0xb9, 0x10, 0xab, // LDA $ab10,Y
0xb9, 0x11, 0xab, // LDA $ab11,Y
0xb9, 0x12, 0xab); // LDA $ab12,Y
cpu.setYRegister(0x32);
cpu.step();
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x0f, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x80, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* CMP - Compare Accumulator - $d9 */
public void test_CMP() throws MemoryAccessException {
bus.write(0xab40, 0x00);
bus.write(0xab41, 0x80);
bus.write(0xab42, 0xff);
cpu.setAccumulator(0x80);
bus.loadProgram(0xd9, 0x10, 0xab, // CMP $ab10,Y
0xd9, 0x11, 0xab, // CMP $ab11,Y
0xd9, 0x12, 0xab); // CMP $ab12,Y
cpu.setYRegister(0x30);
cpu.step();
assertTrue(cpu.getCarryFlag()); // m > y
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag()); // m - y < 0
cpu.step();
assertTrue(cpu.getCarryFlag()); // m = y
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag()); // m - y == 0
cpu.step();
assertFalse(cpu.getCarryFlag()); // m < y
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag()); // $80 - $ff = $81
}
/* SBC - Subtract with Carry - $f9 */
public void test_SBC() throws MemoryAccessException {
bus.write(0xab40, 0x01);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(2);
assertEquals(0xfe, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
bus.loadProgram(0xa9, 0x7f, // LDA #$7f
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(2);
assertEquals(0x7d, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
bus.loadProgram(0xa9, 0x80, // LDA #$80
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(2);
assertEquals(0x7e, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(2);
assertEquals(0xfd, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
bus.loadProgram(0xa9, 0x02, // LDA #$02
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(2);
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
}
public void test_SBC_IncludesNotOfCarry() throws MemoryAccessException {
bus.write(0xab40, 0x01);
// Subtrace with Carry Flag cleared
bus.loadProgram(0x18, // CLC
0xa9, 0x05, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x03, cpu.getAccumulator());
cpu.reset();
// Subtrace with Carry Flag cleared
bus.loadProgram(0x18, // CLC
0xa9, 0x00, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0xfe, cpu.getAccumulator());
cpu.reset();
// Subtract with Carry Flag set
bus.loadProgram(0x38, // SEC
0xa9, 0x05, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x04, cpu.getAccumulator());
assertTrue(cpu.getCarryFlag());
cpu.reset();
// Subtract with Carry Flag set
bus.loadProgram(0x38, // SEC
0xa9, 0x00, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0xff, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag());
}
public void test_SBC_DecimalMode() throws MemoryAccessException {
bus.write(0xab40, 0x01);
bus.write(0xab50, 0x11);
bus.loadProgram(0xf8, // SED
0xa9, 0x00, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x98, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag()); // borrow = set flag
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0xf8, // SED
0xa9, 0x99, // LDA #$99
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x97, cpu.getAccumulator());
assertTrue(cpu.getCarryFlag()); // No borrow = clear flag
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0xf8, // SED
0xa9, 0x50, // LDA #$50
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x48, cpu.getAccumulator());
assertTrue(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0xf8, // SED
0xa9, 0x02, // LDA #$02
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x00, cpu.getAccumulator());
assertTrue(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0xf8, // SED
0xa9, 0x10, // LDA #$10
0xf9, 0x20, 0xab); // SBC $ab20,Y
cpu.setYRegister(0x30);
cpu.step(3);
assertEquals(0x98, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0x38, // SEC
0xf8, // SED
0xa9, 0x05, // LDA #$05
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(4);
assertEquals(0x04, cpu.getAccumulator());
assertTrue(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
cpu.reset();
bus.loadProgram(0x38, // SEC
0xf8, // SED
0xa9, 0x00, // LDA #$00
0xf9, 0x10, 0xab); // SBC $ab10,Y
cpu.setYRegister(0x30);
cpu.step(4);
assertEquals(0x99, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
}
}