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cpu - Change structure of CPU object to group State and Debug info

This commit is contained in:
n loewen 2023-08-28 16:25:43 -04:00
parent 2d210303e6
commit b173d46cb6
1 changed files with 125 additions and 108 deletions
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233
src/cpu.js
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@ -16,39 +16,56 @@ const display = require('./display.js');
// STATE // STATE
const CPU = { const CPU = {
// Core state
running: false,
IP: INITIAL_IP_ADDRESS,
FLAGS: {'C': false, 'Z': false, 'N': false, 'O': false},
FLAGNUMS2NAMES: {0: 'C', 1: 'Z', 2: 'N', 3: 'O'},
Acc: 0,
memory: null,
// Functions that update core state /** Core state **/
state: {
running: false,
IP: INITIAL_IP_ADDRESS,
flags: {'C': false, 'Z': false, 'N': false, 'O': false},
FLAGNUMS2NAMES: {0: 'C', 1: 'Z', 2: 'N', 3: 'O'},
acc: 0,
memory: null,
},
/** Debug info **/
debug: {
previousIP: 0,
currentInstruction: {
opcode: null,
operand: null,
mnemonic: null,
},
cycleCounter: 0,
},
/** Functions that update state **/
/** @param {Uint8Array} data */ /** @param {Uint8Array} data */
loadMemory: (data) => { loadMemory(data) {
CPU.memory = new Uint8Array(256); this.state.memory = new Uint8Array(256);
CPU.memory.set(data, 0); this.state.memory.set(data, 0);
}, },
incrementIP: (offset) => {
CPU.previousIP = CPU.IP;
CPU.IP = CPU.IP + offset;
},
setIP: (address) => {
CPU.previousIP = CPU.IP;
CPU.IP = address;
},
updateFlagZero: () => { CPU.FLAGS.Z = CPU.Acc === 0; },
updateFlagNegative: () => { CPU.Acc & 128 ? CPU.FLAGS.N = true : CPU.FLAGS.N = false },
// Debug info incrementIP(offset) {
previousIP: 0, this.state.previousIP = this.state.IP;
currentInstruction: { this.state.IP = this.state.IP + offset;
opcode: null,
operand: null,
mnemonic: null,
}, },
cycleCounter: 0,
setIP(address) {
this.state.previousIP = this.state.IP;
this.state.IP = address;
},
updateFlagZero() { this.state.flags.Z = this.state.acc === 0; },
updateFlagNegative() { this.state.acc & 128 ? this.state.flags.N = true : this.state.flags.N = false },
/** Hooks **/
onTickHooks: [],
/** @param {function} fn **/
onTick(fn) { this.onTickHooks.push(fn) },
} }
@ -56,154 +73,154 @@ const CPU = {
const Instructions = { const Instructions = {
end: () => { end: () => {
CPU.currentInstruction.mnemonic = 'END'; CPU.debug.currentInstruction.mnemonic = 'END';
CPU.running = false; CPU.state.running = false;
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
store_lit: (lit) => { store_lit: (lit) => {
CPU.currentInstruction.mnemonic = 'STO lit'; CPU.debug.currentInstruction.mnemonic = 'STO lit';
CPU.memory[lit] = CPU.Acc; CPU.state.memory[lit] = CPU.state.acc;
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
store_addr: (addr) => { store_addr: (addr) => {
CPU.currentInstruction.mnemonic = `STO addr; @addr: ${num2hex(CPU.memory[addr])}`; CPU.debug.currentInstruction.mnemonic = `STO addr; @addr: ${num2hex(CPU.state.memory[addr])}`;
CPU.memory[CPU.memory[addr]] = CPU.Acc; CPU.state.memory[CPU.state.memory[addr]] = CPU.state.acc;
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
load_lit: (lit) => { load_lit: (lit) => {
CPU.currentInstruction.mnemonic = 'LDA lit'; CPU.debug.currentInstruction.mnemonic = 'LDA lit';
CPU.Acc = lit; CPU.state.acc = lit;
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
load_addr: (addr) => { load_addr: (addr) => {
CPU.currentInstruction.mnemonic = `LDA addr; @ addr: ${num2hex(CPU.memory[addr])}`; CPU.debug.currentInstruction.mnemonic = `LDA addr; @ addr: ${num2hex(CPU.state.memory[addr])}`;
CPU.Acc = CPU.memory[addr]; CPU.state.acc = CPU.state.memory[addr];
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
add_lit: (lit) => { add_lit: (lit) => {
CPU.currentInstruction.mnemonic = 'ADD lit'; CPU.debug.currentInstruction.mnemonic = 'ADD lit';
// Calculate sum // Calculate sum
let sum = CPU.Acc + lit; let sum = CPU.state.acc + lit;
if (sum > 255) { if (sum > 255) {
CPU.FLAGS.C = true; CPU.state.flags.C = true;
sum = (sum % 255) - 1; sum = (sum % 255) - 1;
} else { } else {
CPU.FLAGS.C = false; CPU.state.flags.C = false;
} }
// Calculate overflow flag status // Calculate overflow flag status
let bitSixCarry = 0; let bitSixCarry = 0;
if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; } if ((CPU.state.acc & 64) && (lit & 64)) { bitSixCarry = 1; }
// let overflow = bitSixCarry ^ (CPU.FLAGS & 8); // let overflow = bitSixCarry ^ (CPU.state.flags & 8);
// FIXME FIXME FIXME // FIXME FIXME FIXME
// I'm on a plane and can't remember how this works // I'm on a plane and can't remember how this works
let overflow = 0; let overflow = 0;
if (overflow) { if (overflow) {
CPU.FLAGS.O = true; CPU.state.flags.O = true;
} else { } else {
CPU.FLAGS.O = false; CPU.state.flags.O = false;
} }
CPU.Acc = sum; CPU.state.acc = sum;
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
add_addr: (addr) => { add_addr: (addr) => {
CPU.currentInstruction.mnemonic = 'ADD addr'; CPU.debug.currentInstruction.mnemonic = 'ADD addr';
// Calculate sum // Calculate sum
let sum = CPU.Acc + CPU.memory[addr]; let sum = CPU.state.acc + CPU.state.memory[addr];
if (sum > 255) { if (sum > 255) {
CPU.FLAGS.C = true; CPU.state.flags.C = true;
sum = (sum % 255) - 1; sum = (sum % 255) - 1;
} else { } else {
CPU.FLAGS.C = false; CPU.state.flags.C = false;
} }
// Calculate overflow flag status // Calculate overflow flag status
let bitSixCarry = 0; let bitSixCarry = 0;
if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; } if ((CPU.state.acc & 64) && (addr & 64)) { bitSixCarry = 1; }
// let overflow = bitSixCarry ^ (CPU.FLAGS & 8); // let overflow = bitSixCarry ^ (CPU.state.flags & 8);
// FIXME FIXME FIXME // FIXME FIXME FIXME
// I'm on a plane and can't remember how this works // I'm on a plane and can't remember how this works
let overflow = 0; let overflow = 0;
if (overflow) { if (overflow) {
CPU.FLAGS.O = true; CPU.state.flags.O = true;
} else { } else {
CPU.FLAGS.O = false; CPU.state.flags.O = false;
} }
CPU.Acc = sum; CPU.state.acc = sum;
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
sub_lit: (lit) => { sub_lit: (lit) => {
CPU.currentInstruction.mnemonic = 'SUB lit'; CPU.debug.currentInstruction.mnemonic = 'SUB lit';
// Calculate sum // Calculate sum
let sum = CPU.Acc - lit; let sum = CPU.state.acc - lit;
if (sum < 0) { if (sum < 0) {
CPU.FLAGS.C = true; CPU.state.flags.C = true;
sum = sum + 256; sum = sum + 256;
} else { } else {
CPU.FLAGS.C = false; CPU.state.flags.C = false;
} }
// Calculate overflow flag status // Calculate overflow flag status
let bitSixCarry = 0; let bitSixCarry = 0;
if ((CPU.Acc & 64) && (lit & 64)) { bitSixCarry = 1; } if ((CPU.state.acc & 64) && (lit & 64)) { bitSixCarry = 1; }
// let overflow = bitSixCarry ^ (CPU.FLAGS & 8); // let overflow = bitSixCarry ^ (CPU.state.flags & 8);
// FIXME FIXME FIXME // FIXME FIXME FIXME
// I'm on a plane and can't remember how this works // I'm on a plane and can't remember how this works
let overflow = 0; let overflow = 0;
if (overflow) { if (overflow) {
CPU.FLAGS.O = true; CPU.state.flags.O = true;
} else { } else {
CPU.FLAGS.O = false; CPU.state.flags.O = false;
} }
CPU.Acc = sum; CPU.state.acc = sum;
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
sub_addr: (addr) => { sub_addr: (addr) => {
CPU.currentInstruction.mnemonic = 'SUB addr'; CPU.debug.currentInstruction.mnemonic = 'SUB addr';
// Calculate sum // Calculate sum
let sum = CPU.Acc - CPU.memory[addr]; let sum = CPU.state.acc - CPU.state.memory[addr];
if (sum < 0) { if (sum < 0) {
CPU.FLAGS.C = true; CPU.state.flags.C = true;
sum = sum + 256; sum = sum + 256;
} else { } else {
CPU.FLAGS.C = false; CPU.state.flags.C = false;
} }
// Calculate overflow flag status // Calculate overflow flag status
let bitSixCarry = 0; let bitSixCarry = 0;
if ((CPU.Acc & 64) && (addr & 64)) { bitSixCarry = 1; } if ((CPU.state.acc & 64) && (addr & 64)) { bitSixCarry = 1; }
// let overflow = bitSixCarry ^ (CPU.FLAGS & 8); // let overflow = bitSixCarry ^ (CPU.state.flags & 8);
// FIXME FIXME FIXME // FIXME FIXME FIXME
// I'm on a plane and can't remember how this works // I'm on a plane and can't remember how this works
let overflow = 0; let overflow = 0;
if (overflow) { if (overflow) {
CPU.FLAGS.O = true; CPU.state.flags.O = true;
} else { } else {
CPU.FLAGS.O = false; CPU.state.flags.O = false;
} }
CPU.Acc = sum; CPU.state.acc = sum;
CPU.updateFlagNegative(); CPU.updateFlagNegative();
CPU.updateFlagZero(); CPU.updateFlagZero();
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
hop_lit: (lit) => { hop_lit: (lit) => {
CPU.currentInstruction.mnemonic = `HOP lit; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`; CPU.debug.currentInstruction.mnemonic = `HOP lit; IP+2: ${CPU.state.memory[CPU.state.IP+2]}, IP+3: ${CPU.state.memory[CPU.state.IP+3]}`;
if (CPU.Acc === lit) { if (CPU.state.acc === lit) {
CPU.incrementIP(4); CPU.incrementIP(4);
} else { } else {
CPU.incrementIP(2); CPU.incrementIP(2);
@ -211,8 +228,8 @@ const Instructions = {
}, },
hop_addr: (addr) => { hop_addr: (addr) => {
CPU.currentInstruction.mnemonic = 'HOP addr'; CPU.debug.currentInstruction.mnemonic = 'HOP addr';
if (CPU.Acc === CPU.memory[addr]) { if (CPU.state.acc === CPU.state.memory[addr]) {
CPU.incrementIP(4); CPU.incrementIP(4);
} else { } else {
CPU.incrementIP(2); CPU.incrementIP(2);
@ -220,13 +237,13 @@ const Instructions = {
}, },
jump_lit: (lit) => { jump_lit: (lit) => {
CPU.currentInstruction.mnemonic = 'JMP lit'; CPU.debug.currentInstruction.mnemonic = 'JMP lit';
CPU.setIP(lit); CPU.setIP(lit);
}, },
jump_addr: (addr) => { jump_addr: (addr) => {
CPU.currentInstruction.mnemonic = 'JMP addr'; CPU.debug.currentInstruction.mnemonic = 'JMP addr';
CPU.setIP(CPU.memory[addr]); CPU.setIP(CPU.state.memory[addr]);
}, },
flag_toggle: (flagNum) => { flag_toggle: (flagNum) => {
@ -235,8 +252,8 @@ const Instructions = {
process.exit(); process.exit();
} }
const flagName = CPU.FLAGNUMS2NAMES[flagNum]; const flagName = CPU.FLAGNUMS2NAMES[flagNum];
CPU.currentInstruction.mnemonic = `FTG ${flagName}`; CPU.debug.currentInstruction.mnemonic = `FTG ${flagName}`;
CPU.FLAGS[flagName] = !CPU.FLAGS[flagName]; CPU.state.flags[flagName] = !CPU.state.flags[flagName];
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
@ -246,8 +263,8 @@ const Instructions = {
process.exit(); process.exit();
} }
const flagName = CPU.FLAGNUMS2NAMES[flagNum]; const flagName = CPU.FLAGNUMS2NAMES[flagNum];
CPU.currentInstruction.mnemonic = `FHP ${flagName}; IP+2: ${CPU.memory[CPU.IP+2]}, IP+3: ${CPU.memory[CPU.IP+3]}`; CPU.debug.currentInstruction.mnemonic = `FHP ${flagName}; IP+2: ${CPU.state.memory[CPU.state.IP+2]}, IP+3: ${CPU.state.memory[CPU.state.IP+3]}`;
if (CPU.FLAGS[CPU.FLAGNUMS2NAMES[flagNum]]) { if (CPU.state.flags[CPU.FLAGNUMS2NAMES[flagNum]]) {
CPU.incrementIP(4); CPU.incrementIP(4);
} else { } else {
CPU.incrementIP(2); CPU.incrementIP(2);
@ -255,7 +272,7 @@ const Instructions = {
}, },
no_op: () => { no_op: () => {
CPU.currentInstruction.mnemonic = `NOP`; CPU.debug.currentInstruction.mnemonic = `NOP`;
CPU.incrementIP(2); CPU.incrementIP(2);
}, },
} }
@ -280,13 +297,13 @@ const opcodes2mnemonics = {
}; };
/** /**
* Load code into memory and set CPU state to "running" * Load code into memory and set CPU state to "state.running"
* @param {Uint8Array} code - Machine code to load * @param {Uint8Array} code - Machine code to load
**/ **/
function startCPU(code) { function startCPU(code) {
CPU.loadMemory(code); CPU.loadMemory(code);
CPU.cycleCounter = 0; CPU.debug.cycleCounter = 0;
CPU.running = true; CPU.state.running = true;
// FIXME: This conflicts with single-stepping // FIXME: This conflicts with single-stepping
// (you can single-step, but keys aren't passed // (you can single-step, but keys aren't passed
@ -309,7 +326,7 @@ function startCPU(code) {
if (key.sequence === '\x03') process.exit(); if (key.sequence === '\x03') process.exit();
let name = key.name.toUpperCase(); let name = key.name.toUpperCase();
if (name in KEY_MAP) { if (name in KEY_MAP) {
CPU.memory[KEYPAD_ADDR] = KEY_MAP[name]; CPU.state.memory[KEYPAD_ADDR] = KEY_MAP[name];
} }
}); });
} }
@ -320,14 +337,14 @@ function startCPU(code) {
* @param {Boolean} [debug] - Print machine status and the line of code being executed * @param {Boolean} [debug] - Print machine status and the line of code being executed
**/ **/
async function stepCPU(debugInfo, debug = false, prettyPrintDisplay = false) { async function stepCPU(debugInfo, debug = false, prettyPrintDisplay = false) {
if (CPU.IP >= CPU.memory.length) { if (CPU.state.IP >= CPU.state.memory.length) {
console.error('HALTING - IP greater than memory size'); console.error('HALTING - IP greater than memory size');
CPU.running = false; CPU.state.running = false;
process.exit(); process.exit();
} else { } else {
CPU.currentInstruction.opcode = CPU.memory[CPU.IP]; CPU.debug.currentInstruction.opcode = CPU.state.memory[CPU.state.IP];
CPU.currentInstruction.operand = CPU.memory[CPU.IP+1]; CPU.debug.currentInstruction.operand = CPU.state.memory[CPU.state.IP+1];
let executeInstruction = opcodes2mnemonics[CPU.currentInstruction.opcode]; let executeInstruction = opcodes2mnemonics[CPU.debug.currentInstruction.opcode];
if (typeof executeInstruction === 'undefined') { if (typeof executeInstruction === 'undefined') {
let info = debugInfo[CPU.previousIP]; let info = debugInfo[CPU.previousIP];
console.error(); console.error();
@ -336,17 +353,17 @@ async function stepCPU(debugInfo, debug = false, prettyPrintDisplay = false) {
console.error(` from line ${info.lineNumber}: ${info.source}`); console.error(` from line ${info.lineNumber}: ${info.source}`);
process.exit(); process.exit();
} }
executeInstruction(CPU.currentInstruction.operand); executeInstruction(CPU.debug.currentInstruction.operand);
CPU.cycleCounter += 1; CPU.debug.cycleCounter += 1;
} }
logCPUState(debugInfo, debug, prettyPrintDisplay); logCPUState(debugInfo, debug, prettyPrintDisplay);
if (DEFAULT_CYCLE_LIMIT) { // Temporary limit as a lazy way to halt infinite loops if (DEFAULT_CYCLE_LIMIT) { // Temporary limit as a lazy way to halt infinite loops
if (CPU.cycleCounter >= DEFAULT_CYCLE_LIMIT) { if (CPU.debug.cycleCounter >= DEFAULT_CYCLE_LIMIT) {
console.warn(' HALTING - reached cycle limit'); console.warn(' HALTING - reached cycle limit');
CPU.running = false; CPU.state.running = false;
} }
} }
if (!CPU.running) process.exit(); if (!CPU.state.running) process.exit();
} }
/** /**
@ -366,7 +383,7 @@ exports.runProgram =
// Animate the output by pausing between steps // Animate the output by pausing between steps
const loop = setInterval(async () => { const loop = setInterval(async () => {
stepCPU(debugInfo, debug, prettyPrint); stepCPU(debugInfo, debug, prettyPrint);
if (!CPU.running) { if (!CPU.state.running) {
logCPUState(debugInfo, debug, prettyPrint); logCPUState(debugInfo, debug, prettyPrint);
console.log('Halted'); console.log('Halted');
process.exit(); process.exit();
@ -383,7 +400,7 @@ exports.runProgram =
**/ **/
exports.singleStepProgram = (code, debugInfo, debug = false, prettyPrintDisplay = false) => { exports.singleStepProgram = (code, debugInfo, debug = false, prettyPrintDisplay = false) => {
startCPU(code); startCPU(code);
while (CPU.running) { while (CPU.state.running) {
stepCPU(debugInfo, debug, prettyPrintDisplay); stepCPU(debugInfo, debug, prettyPrintDisplay);
// FIXME: this prevents exiting with Ctrl+C: // FIXME: this prevents exiting with Ctrl+C:
let key = readlineSync.keyIn('S to step, Q to quit > ', { let key = readlineSync.keyIn('S to step, Q to quit > ', {
@ -402,20 +419,20 @@ exports.singleStepProgram = (code, debugInfo, debug = false, prettyPrintDisplay
**/ **/
function logCPUState(debugInfo, debug = false, prettyPrintDisplay = false) { function logCPUState(debugInfo, debug = false, prettyPrintDisplay = false) {
debugInfo = debugInfo[CPU.previousIP] !== 'undefined' ? debugInfo[CPU.previousIP] : false; debugInfo = debugInfo[CPU.previousIP] !== 'undefined' ? debugInfo[CPU.previousIP] : false;
console.group(`Step ${CPU.cycleCounter}`); console.group(`Step ${CPU.debug.cycleCounter}`);
console.log(); console.log();
if (!debug) console.clear(); if (!debug) console.clear();
display.show(CPU.memory, prettyPrintDisplay); display.show(CPU.state.memory, prettyPrintDisplay);
console.log(); console.log();
if (debugInfo) { if (debugInfo) {
console.log(`Line ${debugInfo.lineNumber}: ${debugInfo.source}`); console.log(`Line ${debugInfo.lineNumber}: ${debugInfo.source}`);
console.log(); console.log();
} }
console.log('Mnemonic:', CPU.currentInstruction.mnemonic); console.log('Mnemonic:', CPU.debug.currentInstruction.mnemonic);
console.log(`Machine: $${num2hex(CPU.currentInstruction.opcode)} $${num2hex(CPU.currentInstruction.operand)}`); console.log(`Machine: $${num2hex(CPU.debug.currentInstruction.opcode)} $${num2hex(CPU.debug.currentInstruction.operand)}`);
console.log(); console.log();
console.log(`IP: $${num2hex(CPU.IP)} Acc: $${num2hex(CPU.Acc)} ONZC ${bool2bit(CPU.FLAGS.O)}${bool2bit(CPU.FLAGS.N)}${bool2bit(CPU.FLAGS.Z)}${bool2bit(CPU.FLAGS.C)}`); console.log(`IP: $${num2hex(CPU.state.IP)} Acc: $${num2hex(CPU.state.acc)} ONZC ${bool2bit(CPU.state.flags.O)}${bool2bit(CPU.state.flags.N)}${bool2bit(CPU.state.flags.Z)}${bool2bit(CPU.state.flags.C)}`);
console.log(`KEY: $${num2hex(CPU.memory[KEYPAD_ADDR])}  ${CPU.running ? "running" : "halted" }`); console.log(`KEY: $${num2hex(CPU.state.memory[KEYPAD_ADDR])}  ${CPU.state.running ? "state.running" : "halted" }`);
console.log(); console.log();
console.log(); console.log();
console.groupEnd(); console.groupEnd();