refactor: remove the ICPU interface

Removing the interface simplifies the code

Author: urish

benchmark/convert-instructions.ts

@@ -8,7 +8,7 @@ let fnBody = '';
 let currentInstruction = '';
 let pattern = '';
 let output = `
-import { ICPU } from '../src/cpu/cpu';
+import { CPU } from '../src/cpu/cpu';
 
 function isTwoWordInstruction(opcode: number) {
   return (
@@ -36,7 +36,7 @@ for (const line of input.split('\n')) {
     patternToFn.push([pattern.trim(), fnName]);
   } else if (line.startsWith('  }')) {
     output += `
-      export function ${fnName}(cpu: ICPU, opcode: number) {
+      export function ${fnName}(cpu: CPU, opcode: number) {
         /*${pattern}*/
         ${fnBody}
         cpu.cycles++;
@@ -62,7 +62,7 @@ for (const [fnPattern, fn] of patternToFn) {
 output += ']';
 
 output += `\n
-export function executeInstruction(idx: number, cpu: ICPU, opcode: number) {
+export function executeInstruction(idx: number, cpu: CPU, opcode: number) {
   switch (idx) {
     ${executeInstructionCases}
     default: instNOP(cpu, opcode);

benchmark/index.ts

@@ -1,4 +1,4 @@
-import { CPU, ICPU } from '../src/cpu/cpu';
+import { CPU } from '../src/cpu/cpu';
 import { avrInstruction } from '../src/cpu/instruction';
 import { createBenchmark } from './benchmark';
 import { permutations } from './permutations';
@@ -21,7 +21,7 @@ function avrInstructionUintArray(cpu: CPU) {
 }
 
 /* Approach 2: use instMap */
-const instructionMap: { [key: number]: (cpu: ICPU, opcode: number) => void } = {};
+const instructionMap: { [key: number]: (cpu: CPU, opcode: number) => void } = {};
 for (const { pattern, fn } of instructions) {
   for (const opcode of permutations(pattern.replace(/ /g, '').substr(0, 16))) {
     if (!instructionMap[opcode]) {

demo/src/cpu-performance.ts

@@ -1,12 +1,12 @@
-import { ICPU } from 'avr8js';
+import { CPU } from 'avr8js';
 
 export class CPUPerformance {
   private prevTime = 0;
   private prevCycles = 0;
   private samples = new Float32Array(64);
   private sampleIndex = 0;
 
-  constructor(private cpu: ICPU, private MHZ: number) {}
+  constructor(private cpu: CPU, private MHZ: number) {}
 
   reset() {
     this.prevTime = 0;

src/cpu/cpu.ts

@@ -11,33 +11,6 @@ import { avrInterrupt } from './interrupt';
 
 const registerSpace = 0x100;
 
-// eslint-disable-next-line @typescript-eslint/interface-name-prefix
-export interface ICPU {
-  readonly data: Uint8Array;
-  readonly dataView: DataView;
-  readonly progMem: Uint16Array;
-  readonly progBytes: Uint8Array;
-
-  /**
-   * Whether the program counter (PC) can address 22 bits (the default is 16)
-   */
-  readonly pc22Bits: boolean;
-
-  /**
-   * Program counter
-   */
-  pc: u32;
-
-  /**
-   * Clock cycle counter
-   */
-  cycles: number;
-
-  readData(addr: u16): u8;
-  writeData(addr: u16, value: u8, mask?: u8): void;
-  onWatchdogReset(): void;
-}
-
 export type CPUMemoryHook = (value: u8, oldValue: u8, addr: u16, mask: u8) => boolean | void;
 export interface CPUMemoryHooks {
   [key: number]: CPUMemoryHook;
@@ -66,7 +39,7 @@ interface AVRClockEventEntry {
   next: AVRClockEventEntry | null;
 }
 
-export class CPU implements ICPU {
+export class CPU {
   readonly data: Uint8Array = new Uint8Array(this.sramBytes + registerSpace);
   readonly data16 = new Uint16Array(this.data.buffer);
   readonly dataView = new DataView(this.data.buffer);
@@ -76,6 +49,10 @@ export class CPU implements ICPU {
   private readonly pendingInterrupts: AVRInterruptConfig[] = [];
   private nextClockEvent: AVRClockEventEntry | null = null;
   private readonly clockEventPool: AVRClockEventEntry[] = []; // helps avoid garbage collection
+
+  /**
+   * Whether the program counter (PC) can address 22 bits (the default is 16)
+   */
   readonly pc22Bits = this.progBytes.length > 0x20000;
 
   readonly gpioPorts = new Set<AVRIOPort>();
@@ -89,8 +66,16 @@ export class CPU implements ICPU {
     /* empty by default */
   };
 
+  /**
+   * Program counter
+   */
   pc: u32 = 0;
-  cycles: u32 = 0;
+
+  /**
+   * Clock cycle counter
+   */
+  cycles = 0;
+
   nextInterrupt: i16 = -1;
 
   constructor(public progMem: Uint16Array, private sramBytes = 8192) {

src/cpu/instruction.ts

@@ -10,7 +10,7 @@
  * Copyright (C) 2019, 2020 Uri Shaked
  */
 
-import { ICPU } from './cpu';
+import { CPU } from './cpu';
 import { u16 } from '../types';
 
 function isTwoWordInstruction(opcode: u16) {
@@ -26,7 +26,7 @@ function isTwoWordInstruction(opcode: u16) {
   );
 }
 
-export function avrInstruction(cpu: ICPU) {
+export function avrInstruction(cpu: CPU) {
   const opcode = cpu.progMem[cpu.pc];
 
   if ((opcode & 0xfc00) === 0x1c00) {

src/cpu/interrupt.ts

@@ -6,9 +6,9 @@
  * Copyright (C) 2019, Uri Shaked
  */
 
-import { ICPU } from './cpu';
+import { CPU } from './cpu';
 
-export function avrInterrupt(cpu: ICPU, addr: number) {
+export function avrInterrupt(cpu: CPU, addr: number) {
   const sp = cpu.dataView.getUint16(93, true);
   cpu.data[sp] = cpu.pc & 0xff;
   cpu.data[sp - 1] = (cpu.pc >> 8) & 0xff;

src/index.ts

@@ -4,7 +4,7 @@
  * Copyright (C) 2019, 2020, Uri Shaked
  */
 
-export { CPU, ICPU, CPUMemoryHook, CPUMemoryHooks } from './cpu/cpu';
+export { CPU, CPUMemoryHook, CPUMemoryHooks } from './cpu/cpu';
 export { avrInstruction } from './cpu/instruction';
 export { avrInterrupt } from './cpu/interrupt';
 export {