package com.loomcom.symon;
import com.loomcom.symon.devices.Memory;
import com.loomcom.symon.exceptions.MemoryAccessException;
import junit.framework.TestCase;
public class CpuZeroPageXModeTest 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 - $15
* ASL - $16
* AND - $35
* ROL - $36
* EOR - $55
*
* LSR - $56
* ADC - $75
* ROR - $76
* STY - $94
* STA - $95
*
* LDY - $b4
* LDA - $b5
* CMP - $d5
* DEC - $d6
* SBC - $f5
*
* INC - $f6
*/
/* ORA - Logical Inclusive OR - $15 */
public void test_ORA() throws MemoryAccessException {
// Set some initial values in zero page.
bus.write(0x30, 0x00);
bus.write(0x32, 0x11);
bus.write(0x34, 0x22);
bus.write(0x38, 0x44);
bus.write(0x40, 0x88);
bus.write(0x02, 0x88);
// Set offset in X register.
cpu.setXRegister(0x30);
bus.loadProgram(0x15, 0x00, // ORA $00,X
0x15, 0x02, // ORA $02,X
0x15, 0x04, // ORA $04,X
0x15, 0x08, // ORA $08,X
0x15, 0x10, // ORA $10,X
0xa9, 0x00, // LDA #$00
0x15, 0xd2); // ORA $d2,X - should wrap around
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());
// Should wrap around and ORA with value in 0x02
cpu.step(2);
assertEquals(0x88, cpu.getAccumulator());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* ASL - Arithmetic Shift Left - $16 */
public void test_ASL() throws MemoryAccessException {
bus.write(0x30, 0x00);
bus.write(0x31, 0x01);
bus.write(0x32, 0x02);
bus.write(0x33, 0x44);
bus.write(0x34, 0x80);
bus.write(0x02, 0x01);
// Set offset in X register.
cpu.setXRegister(0x30);
bus.loadProgram(0x16, 0x00, // ASL $00,X
0x16, 0x01, // ASL $01,X
0x16, 0x02, // ASL $02,X
0x16, 0x03, // ASL $03,X
0x16, 0x04, // ASL $04,X
0x16, 0xd2); // ASL $d2,X
cpu.step();
assertEquals(0x00, bus.read(0x30));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x02, bus.read(0x31));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x04, bus.read(0x32));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x88, bus.read(0x33));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x00, bus.read(0x34));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getCarryFlag());
// Should wrap around, d2 + 30 = 02
cpu.step();
assertEquals(0x02, bus.read(0x02));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
}
/* AND - Logical AND - $35 */
public void test_AND() throws MemoryAccessException {
bus.write(0x30, 0x00);
bus.write(0x31, 0x11);
bus.write(0x32, 0xff);
bus.write(0x33, 0x99);
bus.write(0x34, 0x11);
bus.write(0x35, 0x0f);
bus.write(0x02, 0x11);
// Set offset in X register.
cpu.setXRegister(0x30);
bus.loadProgram(0x35, 0x00, // AND $00
0x35, 0x01, // AND $01,X
0xa9, 0xaa, // LDA #$aa
0x35, 0x02, // AND $02,X
0x35, 0x03, // AND $03
0x35, 0x04, // AND $04,X
0xa9, 0xff, // LDA #$ff
0x35, 0x05, // AND $05,X
0xa9, 0x01, // LDA #$01
0x35, 0xd2); // AND $d2,X
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());
}
/* ROL - Rotate Shift Left - $36 */
public void test_ROL() throws MemoryAccessException {
bus.write(0x70, 0x00);
bus.write(0x71, 0x01);
// Set offset in X register
cpu.setXRegister(0x70);
bus.loadProgram(0x36, 0x00, // ROL $00,X (m=%00000000, c=0)
0x36, 0x01, // ROL $01,X (m=%00000010, c=0)
0x38, // SEC (m=%00000010, c=1)
0x36, 0x01, // ROL $01,X (m=%00000101, c=0)
0x36, 0x01, // ROL $01,X (m=%00001010, c=0)
0x36, 0x01, // ROL $01,X (m=%00010100, c=0)
0x36, 0x01, // ROL $01,X (m=%00101000, c=0)
0x36, 0x01, // ROL $01,X (m=%01010000, c=0)
0x36, 0x01, // ROL $01,X (m=%10100000, c=0)
0x36, 0x01, // ROL $01,X (m=%01000000, c=1)
0x36, 0x01); // ROL $01,X (m=%10000001, c=0)
cpu.step();
assertEquals(0x00, bus.read(0x70));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x02, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step(2);
assertEquals(0x05, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x0a, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x14, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x28, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x50, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0xa0, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x40, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getCarryFlag());
cpu.step();
assertEquals(0x81, bus.read(0x71));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
}
/* EOR - Exclusive OR - $55 */
public void test_EOR() throws MemoryAccessException {
bus.write(0x40, 0x00);
bus.write(0x41, 0xff);
bus.write(0x42, 0x33);
bus.write(0x43, 0x44);
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x88, // LDA #$88
0x55, 0x10, // EOR $10,X
0x55, 0x11, // EOR $11,X
0x55, 0x12, // EOR $12,X
0x55, 0x13); // EOR $13,X
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());
}
/* LSR - Logical Shift Right - $56 */
public void test_LSR() throws MemoryAccessException {
bus.write(0x30, 0x00);
bus.write(0x31, 0x01);
bus.write(0x32, 0x02);
bus.write(0x33, 0x44);
bus.write(0x34, 0x80);
bus.write(0x35, 0x02);
cpu.setXRegister(0x30);
bus.loadProgram(0x56, 0x00, // LSR $00,X
0x56, 0x01, // LSR $01,X
0x56, 0x02, // LSR $02,X
0x56, 0x03, // LSR $03,X
0x56, 0x04, // LSR $04,X
0x38, // SEC
0x56, 0x05); // LSR $05,X
cpu.step();
assertEquals(0x00, bus.read(0x30));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x00, bus.read(0x31));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getCarryFlag());
cpu.step();
assertEquals(0x01, bus.read(0x32));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x22, bus.read(0x33));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x40, bus.read(0x34));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
// Setting Carry should not affect the result.
cpu.step(2);
assertEquals(0x01, bus.read(0x35));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
}
/* ADC - Add with Carry - $75 */
public void test_ADC() throws MemoryAccessException {
bus.write(0x40, 0x01);
bus.write(0x41, 0xff);
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x75, 0x10); // ADC $10,X
cpu.step(2);
assertEquals(0x01, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x7f, // LDA #$7f
0x75, 0x10); // ADC $10,X
cpu.step(2);
assertEquals(0x80, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x80, // LDA #$80
0x75, 0x10); // ADC $10,X
cpu.step(2);
assertEquals(0x81, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0x75, 0x10); // ADC $10,X
cpu.step(2);
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x75, 0x11); // ADC $11,X
cpu.step(2);
assertEquals(0xff, cpu.getAccumulator());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x7f, // LDA #$7f
0x75, 0x11); // ADC $11,X
cpu.step(2);
assertEquals(0x7e, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0x80, // LDA #$80
0x75, 0x11); // ADC $11,X
cpu.step(2);
assertEquals(0x7f, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0x75, 0x11); // ADC $11,X
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(0x40, 0x01);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0x38, // SEC
0x75, 0x10); // ADC $10,X
cpu.setXRegister(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(0x40, 0x01);
bus.write(0x41, 0x99);
bus.loadProgram(0xf8, // SED
0xa9, 0x01, // LDA #$01
0x75, 0x10); // ADC $10,X
cpu.setXRegister(0x30);
cpu.step(3);
assertEquals(0x02, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x49, // LDA #$49
0x75, 0x10); // ADC $10,X
cpu.step(3);
assertEquals(0x50, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x50, // LDA #$50
0x75, 0x10); // ADC $10,X
cpu.step(3);
assertEquals(0x51, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x99, // LDA #$99
0x75, 0x10); // ADC $10,X
cpu.step(3);
assertEquals(0x00, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertTrue(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x00, // LDA #$00
0x75, 0x11); // ADC $10,X
cpu.step(3);
assertEquals(0x99, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x49, // LDA #$49
0x75, 0x11); // ADC $11,X
cpu.step(3);
assertEquals(0x48, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
cpu.setXRegister(0x30);
bus.loadProgram(0xf8, // SED
0xa9, 0x50, // LDA #$59
0x75, 0x11); // ADC $11,X
cpu.step(3);
assertEquals(0x49, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
}
/* ROR - Rotate Right - $76 */
public void test_ROR() throws MemoryAccessException {
bus.write(0x40, 0x00);
bus.write(0x41, 0x10);
bus.loadProgram(0x76, 0x10, // ROR $00 (m=%00000000, c=0)
0x76, 0x11, // ROR $01 (m=%00001000, c=0)
0x76, 0x11, // ROR $01 (m=%00000100, c=0)
0x76, 0x11, // ROR $01 (m=%00000010, c=0)
0x76, 0x11, // ROR $01 (m=%00000001, c=0)
0x76, 0x11, // ROR $01 (m=%00000000, c=1)
0x76, 0x11, // ROR $01 (m=%10000000, c=0)
0x76, 0x11, // ROR $01 (m=%01000000, c=0)
0x76, 0x11, // ROR $01 (m=%00100000, c=0)
0x76, 0x11); // ROR $01 (m=%00010000, c=0)
cpu.setXRegister(0x30);
cpu.step();
assertEquals(0x00, bus.read(0x40));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x08, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x04, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x02, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x01, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x00, bus.read(0x41));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getCarryFlag());
cpu.step();
assertEquals(0x80, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x40, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x20, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
cpu.step();
assertEquals(0x10, bus.read(0x41));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getCarryFlag());
}
/* STY - Store Y Register - $94 */
public void test_STY() throws MemoryAccessException {
cpu.setXRegister(0x30);
cpu.setYRegister(0x00);
bus.loadProgram(0x94, 0x10); // STY $10,X
cpu.step();
assertEquals(0x00, bus.read(0x40));
// Should have no effect on flags.
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setXRegister(0x30);
cpu.setYRegister(0x0f);
bus.loadProgram(0x94, 0x10); // STY $10,X
cpu.step();
assertEquals(0x0f, bus.read(0x40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setXRegister(0x30);
cpu.setYRegister(0x80);
bus.loadProgram(0x94, 0x10); // STY $10,X
cpu.step();
assertEquals(0x80, bus.read(0x40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
}
/* STA - Store Accumulator - $95 */
public void test_STA() throws MemoryAccessException {
cpu.setXRegister(0x30);
cpu.setAccumulator(0x00);
bus.loadProgram(0x95, 0x10); // STA $10,X
cpu.step();
assertEquals(0x00, bus.read(0x40));
// Should have no effect on flags.
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setXRegister(0x30);
cpu.setAccumulator(0x0f);
bus.loadProgram(0x95, 0x10); // STA $10,X
cpu.step();
assertEquals(0x0f, bus.read(0x40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.reset();
cpu.setXRegister(0x30);
cpu.setAccumulator(0x80);
bus.loadProgram(0x95, 0x10); // STA $10,X
cpu.step();
assertEquals(0x80, bus.read(0x40));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
}
/* LDY - Load Y Register - $b4 */
public void test_LDY() throws MemoryAccessException {
bus.write(0x45, 0x00);
bus.write(0x46, 0x0f);
bus.write(0x47, 0x80);
bus.loadProgram(0xb4, 0x10, // LDY $10,X
0xb4, 0x11, // LDY $11,X
0xb4, 0x12); // LDY $12,X
cpu.setXRegister(0x35);
cpu.step();
assertEquals(0x00, cpu.getYRegister());
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x0f, cpu.getYRegister());
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x80, cpu.getYRegister());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* LDA - Load Accumulator - $b5 */
public void test_LDA() throws MemoryAccessException {
bus.write(0x42, 0x00);
bus.write(0x43, 0x0f);
bus.write(0x44, 0x80);
bus.loadProgram(0xb5, 0x10, // LDA $10,X
0xb5, 0x11, // LDA $11,X
0xb5, 0x12); // LDA $12,X
cpu.setXRegister(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 - $d5 */
public void test_CMP() throws MemoryAccessException {
bus.write(0x40, 0x00);
bus.write(0x41, 0x80);
bus.write(0x42, 0xff);
cpu.setAccumulator(0x80);
bus.loadProgram(0xd5, 0x10,
0xd5, 0x11,
0xd5, 0x12);
cpu.setXRegister(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()); // m - y < 0
}
/* DEC - Decrement Memory Location - $d6 */
public void test_DEC() throws MemoryAccessException {
bus.write(0x40, 0x00);
bus.write(0x41, 0x01);
bus.write(0x42, 0x80);
bus.write(0x43, 0xff);
bus.loadProgram(0xd6, 0x10, // DEC $10,X
0xd6, 0x11, // DEC $11,X
0xd6, 0x12, // DEC $12,X
0xd6, 0x13); // DEC $13,X
cpu.setXRegister(0x30);
cpu.step();
assertEquals(0xff, bus.read(0x40));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x00, bus.read(0x41));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x7f, bus.read(0x42));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0xfe, bus.read(0x43));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
}
/* SBC - Subtract with Carry - $f5 */
public void test_SBC() throws MemoryAccessException {
bus.write(0x40, 0x01);
bus.loadProgram(0xa9, 0x00, // LDA #$00
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(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
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(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
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(0x30);
cpu.step(2);
assertEquals(0x7e, cpu.getAccumulator());
assertFalse(cpu.getNegativeFlag());
assertTrue(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getCarryFlag());
cpu.reset();
bus.loadProgram(0xa9, 0xff, // LDA #$ff
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(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
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(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(0x40, 0x01);
// Subtrace with Carry Flag cleared
bus.loadProgram(0x18, // CLC
0xa9, 0x05, // LDA #$00
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(0x30);
cpu.step(3);
assertEquals(0x03, cpu.getAccumulator());
cpu.reset();
// Subtrace with Carry Flag cleared
bus.loadProgram(0x18, // CLC
0xa9, 0x00, // LDA #$00
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(0x30);
cpu.step(3);
assertEquals(0xfe, cpu.getAccumulator());
cpu.reset();
// Subtract with Carry Flag set
bus.loadProgram(0x38, // SEC
0xa9, 0x05, // LDA #$00
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(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
0xf5, 0x10); // SBC $10,X
cpu.setXRegister(0x30);
cpu.step(3);
assertEquals(0xff, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag());
}
public void test_SBC_DecimalMode() throws MemoryAccessException {
bus.write(0x40, 0x01);
bus.write(0x50, 0x11);
bus.loadProgram(0xf8,
0xa9, 0x00,
0xf5, 0x10);
cpu.setXRegister(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,
0xa9, 0x99,
0xf5, 0x10);
cpu.setXRegister(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,
0xa9, 0x50,
0xf5, 0x10);
cpu.setXRegister(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
0xf5, 0x10); // SBC $10
cpu.setXRegister(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
0xf5, 0x20); // SBC $20
cpu.setXRegister(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
0xf5, 0x10); // SBC $10
cpu.setXRegister(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
0xf5, 0x10); // SBC $10
cpu.setXRegister(0x30);
cpu.step(4);
assertEquals(0x99, cpu.getAccumulator());
assertFalse(cpu.getCarryFlag());
assertFalse(cpu.getNegativeFlag());
assertFalse(cpu.getOverflowFlag());
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getDecimalModeFlag());
}
/* INC - Increment Memory Location - $f6 */
public void test_INC() throws MemoryAccessException {
bus.write(0x30, 0x00);
bus.write(0x31, 0x7f);
bus.write(0x32, 0xff);
cpu.setXRegister(0x20);
bus.loadProgram(0xf6, 0x10, // INC $10,X
0xf6, 0x11, // INC $11,X
0xf6, 0x12); // INC $12,X
cpu.step();
assertEquals(0x01, bus.read(0x30));
assertFalse(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x80, bus.read(0x31));
assertFalse(cpu.getZeroFlag());
assertTrue(cpu.getNegativeFlag());
cpu.step();
assertEquals(0x00, bus.read(0x32));
assertTrue(cpu.getZeroFlag());
assertFalse(cpu.getNegativeFlag());
}
}