First pass it more accurate cycle counting.

This commit is contained in:
Will Scullin 2019-09-18 18:46:26 -07:00
parent 7b72d8a9d2
commit 8ee543619e
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GPG Key ID: 9092A5C0A673416B
4 changed files with 2365 additions and 66 deletions

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@ -41,7 +41,8 @@
}, {
"files": [ "test/*"],
"env": {
"jest": true
"jest": true,
"node": true
}
}, {
"files": [ "js/entry2.js", "js/entry2e.js"],

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@ -94,7 +94,6 @@ export default function CPU6502(options)
var readPages = [];
var writePages = [];
var resetHandlers = [];
var inCallback = false;
var cycles = 0;
var sync = false;
@ -164,10 +163,12 @@ export default function CPU6502(options)
}
function increment(a) {
cycles += 1;
return testNZ((a + 0x01) & 0xff);
}
function decrement(a) {
cycles += 1;
return testNZ((a + 0xff) & 0xff);
}
@ -176,14 +177,26 @@ export default function CPU6502(options)
page = addr >> 8,
off = addr & 0xff;
return readPages[page].read(page, off, dbg);
var result = readPages[page].read(page, off, dbg);
if (!dbg) {
cycles++;
}
return result;
}
function readByte(addr, dbg) {
var page = addr >> 8,
off = addr & 0xff;
return readPages[page].read(page, off, dbg);
var result = readPages[page].read(page, off, dbg);
if (!dbg) {
cycles += 1;
}
return result;
}
function writeByte(addr, val) {
@ -191,6 +204,8 @@ export default function CPU6502(options)
off = addr & 0xff;
writePages[page].write(page, off, val);
cycles += 1;
}
function readWord(addr, dbg) {
@ -210,24 +225,54 @@ export default function CPU6502(options)
return (msb << 8) | lsb;
}
function pushByte(val) {
function rawPushByte(val) {
writeByte(loc.STACK | sp, val);
sp = (sp + 0xff) & 0xff;
}
function pushWord(val) {
pushByte(val >> 8);
pushByte(val & 0xff);
function rawPushWord(val) {
rawPushByte(val >> 8);
rawPushByte(val & 0xff);
}
function pullByte() {
function pushByte(val) {
writeByte(loc.STACK | sp, val);
sp = (sp + 0xff) & 0xff;
cycles += 1;
}
function pushWord(val) {
writeByte(loc.STACK | sp, val >> 8);
sp = (sp + 0xff) & 0xff;
writeByte(loc.STACK | sp, val) & 0xff;
sp = (sp + 0xff) & 0xff;
cycles += 1;
}
function rawPullByte() {
sp = (sp + 0x01) & 0xff;
return readByte(loc.STACK | sp);
}
function rawPullWord() {
var lsb = rawPullByte(loc.STACK | sp);
var msb = rawPullByte(loc.STACK | sp);
return (msb << 8) | lsb;
}
function pullByte() {
sp = (sp + 0x01) & 0xff;
var result = readByte(loc.STACK | sp);
cycles +=2;
return result;
}
function pullWord() {
var lsb = pullByte(),
msb = pullByte();
var lsb = rawPullByte(loc.STACK | sp);
var msb = rawPullByte(loc.STACK | sp);
cycles += 2;
return (msb << 8) | lsb;
}
@ -287,17 +332,23 @@ export default function CPU6502(options)
// $00,X
function readZeroPageX() {
return readByte((readBytePC() + xr) & 0xff);
var result = readByte((readBytePC() + xr) & 0xff);
cycles++;
return result;
}
// $00,Y
function readZeroPageY() {
return readByte((readBytePC() + yr) & 0xff);
var addr = (readBytePC() + yr) & 0xff;
cycles++;
return readByte(addr);
}
// ($00,X)
function readZeroPageXIndirect() {
return readByte(readZPWord((readBytePC() + xr) & 0xff));
var addr = readZPWord((readBytePC() + xr) & 0xff);
cycles++;
return readByte(addr);
}
// ($00),Y
@ -332,32 +383,44 @@ export default function CPU6502(options)
// $0000,X
function writeAbsoluteX(val) {
writeByte((readWordPC() + xr) & 0xffff, val);
var address = (readWordPC() + xr) & 0xffff;
cycles++;
writeByte(address, val);
}
// $0000,Y
function writeAbsoluteY(val) {
writeByte((readWordPC() + yr) & 0xffff, val);
var address = (readWordPC() + yr) & 0xffff;
cycles++;
writeByte(address, val);
}
// $00,X
function writeZeroPageX(val) {
writeByte((readBytePC() + xr) & 0xff, val);
var address = (readBytePC() + xr) & 0xff;
cycles++;
writeByte(address, val);
}
// $00,Y
function writeZeroPageY(val) {
writeByte((readBytePC() + yr) & 0xff, val);
var address = (readBytePC() + yr) & 0xff;
cycles++;
writeByte(address, val);
}
// ($00,X)
function writeZeroPageXIndirect(val) {
writeByte(readZPWord((readBytePC() + xr) & 0xff), val);
var address = readZPWord((readBytePC() + xr) & 0xff);
cycles++;
writeByte(address, val);
}
// ($00),Y
function writeZeroPageIndirectY(val) {
writeByte((readZPWord(readBytePC()) + yr) & 0xffff, val);
var address = (readZPWord(readBytePC()) + yr) & 0xffff;
cycles++;
writeByte(address, val);
}
// ($00) (65C02)
@ -372,7 +435,9 @@ export default function CPU6502(options)
// $00,X
function readAddrZeroPageX() {
return (readBytePC() + xr) & 0xff;
var result = (readBytePC() + xr) & 0xff;
cycles++;
return result;
}
// $0000 (65C02)
@ -387,7 +452,9 @@ export default function CPU6502(options)
// ($0000) (65C02)
function readAddrAbsoluteIndirect() {
return readWord(readWordPC());
var address = readWordPC();
cycles++;
return readWord(address);
}
// $0000,X
@ -395,20 +462,24 @@ export default function CPU6502(options)
var addr = readWordPC();
if (!is65C02) {
readByte(addr);
} else {
cycles++;
}
return (addr + xr) & 0xffff;
}
// $(0000,X)
function readAddrAbsoluteXIndirect() {
return readWord((readWordPC() + xr) & 0xffff);
var address = (readWordPC() + xr) & 0xffff;
cycles++;
return readWord(address);
}
/* Break */
function brk(readFn) {
readFn();
pushWord(pc);
php();
rawPushWord(pc);
rawPushByte(sr | flags.B);
if (is65C02) {
setFlag(flags.D, false);
}
@ -503,6 +574,7 @@ export default function CPU6502(options)
function shiftLeft(val) {
setFlag(flags.C, val & 0x80);
cycles++;
return testNZ((val << 1) & 0xff);
}
@ -518,6 +590,7 @@ export default function CPU6502(options)
function shiftRight(val) {
setFlag(flags.C, val & 0x01);
cycles++;
return testNZ(val >> 1);
}
@ -534,6 +607,7 @@ export default function CPU6502(options)
function rotateLeft(val) {
var c = (sr & flags.C);
setFlag(flags.C, val & 0x80);
cycles++;
return testNZ(((val << 1) | (c ? 0x01 : 0x00)) & 0xff);
}
@ -550,6 +624,7 @@ export default function CPU6502(options)
function rotateRight(a) {
var c = (sr & flags.C);
setFlag(flags.C, a & 0x01);
cycles++;
return testNZ((a >> 1) | (c ? 0x80 : 0x00));
}
@ -585,6 +660,7 @@ export default function CPU6502(options)
var addr = readBytePC();
var val = readByte(addr);
val &= bit;
cycles++;
writeByte(addr, val);
}
@ -595,6 +671,7 @@ export default function CPU6502(options)
var addr = readBytePC();
var val = readByte(addr);
val |= bit;
cycles++;
writeByte(addr, val);
}
@ -603,6 +680,7 @@ export default function CPU6502(options)
var addr = readAddrFn(),
val = readByte(addr);
testZ(val & ar);
cycles++;
writeByte(addr, val & ~ar);
}
@ -611,6 +689,7 @@ export default function CPU6502(options)
var addr = readAddrFn(),
val = readByte(addr);
testZ(val & ar);
cycles++;
writeByte(addr, val | ar);
}
@ -674,6 +753,7 @@ export default function CPU6502(options)
function bbr(b) {
var val = readZeroPage();
var off = readBytePC(); // changes pc
cycles++;
if (((1 << b) & val) === 0) {
pc += off > 127 ? off - 256 : off;
}
@ -682,23 +762,24 @@ export default function CPU6502(options)
function bbs(b) {
var val = readZeroPage(); // ZP
var off = readBytePC(); // changes pc
cycles++;
if (((1 << b) & val) !== 0) {
pc += off > 127 ? off - 256 : off;
}
}
/* Transfers and stack */
function tax() { testNZ(xr = ar); }
function tax() { testNZ(xr = ar); cycles += 1; }
function txa() { testNZ(ar = xr); }
function txa() { testNZ(ar = xr); cycles += 1; }
function tay() { testNZ(yr = ar); }
function tay() { testNZ(yr = ar); cycles += 1; }
function tya() { testNZ(ar = yr); }
function tya() { testNZ(ar = yr); cycles += 1; }
function tsx() { testNZ(xr = sp); }
function tsx() { testNZ(xr = sp); cycles += 1; }
function txs() { sp = xr; }
function txs() { sp = xr; cycles += 1; }
function pha() { pushByte(ar); }
@ -731,26 +812,31 @@ export default function CPU6502(options)
/* Return from Subroutine */
function rts() {
pc = (pullWord() + 1) & 0xffff;
cycles += 1;
}
/* Return from Subroutine */
function rti() {
sr = pullByte() & ~flags.B;
pc = pullWord();
sr = rawPullByte() & ~flags.B;
pc = rawPullWord();
cycles += 2;
}
/* Set and Clear */
function set(flag) {
sr |= flag;
cycles += 1;
}
function clr(flag) {
sr &= ~flag;
cycles += 1;
}
/* No-Op */
function nop(readAddrFn) {
readAddrFn();
cycles += 1;
}
var ops = {
@ -871,8 +957,8 @@ export default function CPU6502(options)
// AND
0x29: ['AND', and, readImmediate, modes.immediate, 2],
0x25: ['AND', and, readZeroPage, modes.zeroPage, 2],
0x35: ['AND', and, readZeroPageX, modes.zeroPageX, 3],
0x25: ['AND', and, readZeroPage, modes.zeroPage, 3],
0x35: ['AND', and, readZeroPageX, modes.zeroPageX, 4],
0x2D: ['AND', and, readAbsolute, modes.absolute, 4],
0x3D: ['AND', and, readAbsoluteX, modes.absoluteX, 4],
0x39: ['AND', and, readAbsoluteY, modes.absoluteY, 4],
@ -881,8 +967,8 @@ export default function CPU6502(options)
// ORA
0x09: ['ORA', ora, readImmediate, modes.immediate, 2],
0x05: ['ORA', ora, readZeroPage, modes.zeroPage, 2],
0x15: ['ORA', ora, readZeroPageX, modes.zeroPageX, 3],
0x05: ['ORA', ora, readZeroPage, modes.zeroPage, 3],
0x15: ['ORA', ora, readZeroPageX, modes.zeroPageX, 4],
0x0D: ['ORA', ora, readAbsolute, modes.absolute, 4],
0x1D: ['ORA', ora, readAbsoluteX, modes.absoluteX, 4],
0x19: ['ORA', ora, readAbsoluteY, modes.absoluteY, 4],
@ -1139,9 +1225,6 @@ export default function CPU6502(options)
if (is65C02) {
for (var key in cops) {
if (cops.hasOwnProperty(key)) {
if (key in ops) {
debug('overriding opcode ' + toHex(key));
}
ops[key] = cops[key];
}
}
@ -1162,10 +1245,8 @@ export default function CPU6502(options)
unk = [
'???',
function() {
/*
debug('Unknown OpCode: ' + toHex(b) +
' at ' + toHex(pc - 1, 4));
*/
},
readImplied,
modes.implied,
@ -1266,18 +1347,14 @@ export default function CPU6502(options)
sync = true;
var op = opary[readBytePC()];
sync = false;
op[1](op[2]);
cycles += op[4];
if (cb) {
inCallback = true;
cb(this);
inCallback = false;
}
},
stepN: function(n) {
stepDebug: function(n, cb) {
var op, idx;
for (idx = 0; idx < n; idx++) {
@ -1285,7 +1362,10 @@ export default function CPU6502(options)
op = opary[readBytePC()];
sync = false;
op[1](op[2]);
cycles += op[4];
if (cb) {
cb(this);
}
}
},
@ -1297,7 +1377,6 @@ export default function CPU6502(options)
op = opary[readBytePC()];
sync = false;
op[1](op[2]);
cycles += op[4];
}
},
@ -1305,21 +1384,14 @@ export default function CPU6502(options)
{
var op, end = cycles + c;
if (inCallback) {
return;
}
while (cycles < end) {
sync = true;
op = opary[readBytePC()];
sync = false;
op[1](op[2]);
cycles += op[4];
if (cb) {
inCallback = true;
cb(this);
inCallback = false;
}
}
},

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@ -3,6 +3,7 @@ import CPU6502 from '../js/cpu6502';
import Test6502 from '../js/roms/6502test';
import Test65C02 from '../js/roms/65C02test';
describe('CPU', function () {
var cpu;
var lastPC = 0;
var done = false;
@ -13,7 +14,6 @@ function traceCB() {
lastPC = pc;
}
describe('CPU', function () {
describe('6502', function () {
it('completes the test ROM', function () {
cpu = new CPU6502();

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test/cpu6502.spec.js Normal file

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