package com.loomcom.symon;
import com.loomcom.symon.devices.Memory;
import com.loomcom.symon.exceptions.MemoryAccessException;
import junit.framework.TestCase;
public class CpuRelativeModeTest 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:
*
* BPL - Branch if Positive - 0x10
* BMI - Branch if Minus - 0x30
* BVC - Branch if Overflow Clear - 0x50
* BVS - Branch if Overflow Set - 0x70
* BCC - Branch if Carry Clear - 0x90
* BCS - Branch if Carry Set - 0xb0
* BNE - Branch if Not Equal to Zero - 0xd0
* BEQ - Branch if Equal to Zero - 0xf0
*
*/
/* BPL - Branch if Positive - 0x10 */
public void test_BPL() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0x10, 0x05); // BPL $05 ; *=$0202+$05 ($0207)
cpu.setNegativeFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x10, 0x05); // BPL $05 ; *=$0202+$05 ($0207)
cpu.clearNegativeFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0x10, 0xfb); // BPL $fb ; *=$0202-$05 ($01fd)
cpu.setNegativeFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x10, 0xfb); // BPL $fb ; *=$0202-$05 ($01fd)
cpu.clearNegativeFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
}
/* BMI - Branch if Minus - 0x30 */
public void test_BMI() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0x30, 0x05); // BMI $05 ; *=$0202+$05 ($0207)
cpu.setNegativeFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x30, 0x05); // BMI $05 ; *=$0202+$05 ($0207)
cpu.clearNegativeFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0x30, 0xfb); // BMI $fb ; *=$0202-$05 ($01fd)
cpu.setNegativeFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x30, 0xfb); // BMI $fb ; *=$0202-$05 ($01fd)
cpu.clearNegativeFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
}
/* BVC - Branch if Overflow Clear - 0x50 */
public void test_BVC() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0x50, 0x05); // BVC $05 ; *=$0202+$05 ($0207)
cpu.setOverflowFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x50, 0x05); // BVC $05 ; *=$0202+$05 ($0207)
cpu.clearOverflowFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0x50, 0xfb); // BVC $fb ; *=$0202-$05 ($01fd)
cpu.setOverflowFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x50, 0xfb); // BVC $fb ; *=$0202-$05 ($01fd)
cpu.clearOverflowFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
}
/* BVS - Branch if Overflow Set - 0x70 */
public void test_BVS() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0x70, 0x05); // BVS $05 ; *=$0202+$05 ($0207)
cpu.setOverflowFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x70, 0x05); // BVS $05 ; *=$0202+$05 ($0207)
cpu.clearOverflowFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0x70, 0xfb); // BVS $fb ; *=$0202-$05 ($01fd)
cpu.setOverflowFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x70, 0xfb); // BVS $fb ; *=$0202-$05 ($01fd)
cpu.clearOverflowFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
}
/* BCC - Branch if Carry Clear - 0x90 */
public void test_BCC() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0x90, 0x05); // BCC $05 ; *=$0202+$05 ($0207)
cpu.setCarryFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x90, 0x05); // BCC $05 ; *=$0202+$05 ($0207)
cpu.clearCarryFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0x90, 0xfb); // BCC $fb ; *=$0202-$05 ($01fd)
cpu.setCarryFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0x90, 0xfb); // BCC $fb ; *=$0202-$05 ($01fd)
cpu.clearCarryFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
}
/* BCS - Branch if Carry Set - 0xb0 */
public void test_BCS() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0xb0, 0x05); // BCS $05 ; *=$0202+$05 ($0207)
cpu.setCarryFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xb0, 0x05); // BCS $05 ; *=$0202+$05 ($0207)
cpu.clearCarryFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0xb0, 0xfb); // BCS $fb ; *=$0202-$05 ($01fd)
cpu.setCarryFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xb0, 0xfb); // BCS $fb ; *=$0202-$05 ($01fd)
cpu.clearCarryFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
}
/* BNE - Branch if Not Equal to Zero - 0xd0 */
public void test_BNE() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0xd0, 0x05); // BNE $05 ; *=$0202+$05 ($0207)
cpu.setZeroFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xd0, 0x05); // BNE $05 ; *=$0202+$05 ($0207)
cpu.clearZeroFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0xd0, 0xfb); // BNE $fb ; *=$0202-$05 ($01fd)
cpu.setZeroFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xd0, 0xfb); // BNE $fb ; *=$0202-$05 ($01fd)
cpu.clearZeroFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
}
/* BEQ - Branch if Equal to Zero - 0xf0 */
public void test_BEQ() throws MemoryAccessException {
// Positive Offset
bus.loadProgram(0xf0, 0x05); // BEQ $05 ; *=$0202+$05 ($0207)
cpu.setZeroFlag();
cpu.step();
assertEquals(0x207, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xf0, 0x05); // BEQ $05 ; *=$0202+$05 ($0207)
cpu.clearZeroFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
// Negative Offset
cpu.reset();
bus.loadProgram(0xf0, 0xfb); // BEQ $fb ; *=$0202-$05 ($01fd)
cpu.setZeroFlag();
cpu.step();
assertEquals(0x1fd, cpu.getProgramCounter());
cpu.reset();
bus.loadProgram(0xf0, 0xfb); // BEQ $fb ; *=$0202-$05 ($01fd)
cpu.clearZeroFlag();
cpu.step();
assertEquals(0x202, cpu.getProgramCounter());
}
}