Seth Morabito
2ebdd254b3
This is something of a "Work in Progress" checkpoint of several features that are all half baked: 1. Allow loading of 16KB ROM files at address $C000 at run-time, not just at startup. See the "Load ROM..." File menu item. 2. Introduces the notion of "CPU Behaviors", so the core 6502 CPU implementation can match the behavior of either an early NMOS 6502, late NMOS 6502, or CMOS 65C02. Very little of this is actually implemented so far. 3. Adds a completely bogus implementation of the 6522 VIA (it does absolutely nothing right now). 4. Changes the address of the ACIA in the simulated system to match a real hardware implementation I put together.
103 lines
3.3 KiB
Java
103 lines
3.3 KiB
Java
package com.loomcom.symon;
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import com.loomcom.symon.devices.Memory;
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import com.loomcom.symon.exceptions.MemoryAccessException;
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import com.loomcom.symon.InstructionTable;
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import junit.framework.TestCase;
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public class CpuIndirectModeTest extends TestCase {
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protected Cpu cpu;
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protected Bus bus;
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protected Memory mem;
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protected void setUp() throws Exception {
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this.cpu = new Cpu();
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this.bus = new Bus(0x0000, 0xffff);
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this.mem = new Memory(0x0000, 0x10000);
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bus.addCpu(cpu);
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bus.addDevice(mem);
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// Load the reset vector.
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bus.write(0xfffc, Bus.DEFAULT_LOAD_ADDRESS & 0x00ff);
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bus.write(0xfffd, (Bus.DEFAULT_LOAD_ADDRESS & 0xff00) >>> 8);
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cpu.reset();
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// Assert initial state
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assertEquals(0, cpu.getAccumulator());
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assertEquals(0, cpu.getXRegister());
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assertEquals(0, cpu.getYRegister());
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assertEquals(0x200, cpu.getProgramCounter());
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assertEquals(0xff, cpu.getStackPointer());
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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/*
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* The following opcodes are tested for correctness in this file:
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*
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* JMP - $6c
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*
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*/
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/* JMP - Jump - $6c */
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public void test_JMP_notOnPageBoundary() throws MemoryAccessException {
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bus.write(0x3400, 0x00);
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bus.write(0x3401, 0x54);
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bus.loadProgram(0x6c, 0x00, 0x34);
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cpu.step();
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assertEquals(0x5400, cpu.getProgramCounter());
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// No change to status flags.
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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public void test_JMP_with_ROR_Bug() throws MemoryAccessException {
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cpu.setBehavior(Cpu.CpuBehavior.NMOS_WITH_ROR_BUG);
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bus.write(0x3400, 0x22);
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bus.write(0x34ff, 0x00);
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bus.write(0x3500, 0x54);
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bus.loadProgram(0x6c, 0xff, 0x34);
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cpu.step();
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assertEquals(0x2200, cpu.getProgramCounter());
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// No change to status flags.
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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public void test_JMP_withIndirectBug() throws MemoryAccessException {
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cpu.setBehavior(Cpu.CpuBehavior.NMOS_WITH_INDIRECT_JMP_BUG);
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bus.write(0x3400, 0x22);
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bus.write(0x34ff, 0x00);
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bus.write(0x3500, 0x54);
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bus.loadProgram(0x6c, 0xff, 0x34);
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cpu.step();
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assertEquals(0x2200, cpu.getProgramCounter());
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// No change to status flags.
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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public void test_JMP_withOutIndirectBug() throws MemoryAccessException {
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cpu.setBehavior(Cpu.CpuBehavior.NMOS_WITHOUT_INDIRECT_JMP_BUG);
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bus.write(0x3400, 0x22);
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bus.write(0x34ff, 0x00);
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bus.write(0x3500, 0x54);
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bus.loadProgram(0x6c, 0xff, 0x34);
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cpu.step();
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assertEquals(0x5400, cpu.getProgramCounter());
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// No change to status flags.
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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public void test_JMP_cmos() throws MemoryAccessException {
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cpu.setBehavior(Cpu.CpuBehavior.CMOS);
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bus.write(0x3400, 0x22);
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bus.write(0x34ff, 0x00);
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bus.write(0x3500, 0x54);
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bus.loadProgram(0x6c, 0xff, 0x34);
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cpu.step();
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assertEquals(0x5400, cpu.getProgramCounter());
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// No change to status flags.
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assertEquals(0x20, cpu.getProcessorStatus());
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}
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} |