feat: implement some AVR instructions + tests

6 files changed, 626 insertions, 8 deletions

diff --git a/src/cpu.ts b/src/cpu.ts
new file mode 100644
index 0000000..a6e0ab6
--- /dev/null
+++ b/src/cpu.ts
@@ -0,0 +1,43 @@
+import { u16, u8 } from './types';
+
+export interface ICPU {
+  readonly data: Uint8Array;
+  readonly dataView: DataView;
+  readonly progMem: Uint16Array;
+  readonly progBytes: Uint8Array;
+  pc: u16;
+  cycles: number;
+
+  readData(addr: u16): u8;
+  writeData(addr: u16, value: u8): void;
+}
+
+export type ICPUMemoryHook = (value: u8, oldValue: u8, addr: u16) => void;
+export interface ICPUMemoryHooks {
+  [key: number]: ICPUMemoryHook;
+}
+
+export class CPU implements ICPU {
+  readonly data = new Uint8Array(16384);
+  readonly data16 = new Uint16Array(this.data.buffer);
+  readonly dataView = new DataView(this.data.buffer);
+  readonly progBytes = new Uint8Array(this.progMem.buffer);
+  readonly writeHooks: ICPUMemoryHooks = [];
+
+  pc = 0;
+  cycles = 0;
+
+  constructor(public progMem: Uint16Array) {}
+
+  readData(addr: number) {
+    return this.data[addr];
+  }
+
+  writeData(addr: number, value: number) {
+    const hook = this.writeHooks[addr];
+    if (hook) {
+      hook(value, this.data[addr], addr);
+    }
+    this.data[addr] = value;
+  }
+}
diff --git a/src/index.spec.ts b/src/index.spec.ts
deleted file mode 100644
index 9f3fef3..0000000
--- a/src/index.spec.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-import { x } from './index';
-
-describe('index', () => {
-  it('should export x = 1', () => {
-    expect(x).toEqual(1);
-  });
-});
diff --git a/src/index.ts b/src/index.ts
index ad1d380..038ff16 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1 +1,2 @@
-export const x = 1;
+export { CPU, ICPU, ICPUMemoryHook, ICPUMemoryHooks } from './cpu';
+export { avrInstruction } from './instruction';
diff --git a/src/instruction.spec.ts b/src/instruction.spec.ts
new file mode 100644
index 0000000..9ea4c0f
--- /dev/null
+++ b/src/instruction.spec.ts
@@ -0,0 +1,78 @@
+import { CPU, ICPU } from './cpu';
+import { avrInstruction } from './instruction';
+
+describe('avrInstruction', () => {
+  let cpu: CPU;
+
+  beforeEach(() => {
+    cpu = new CPU(new Uint16Array(0x8000));
+  });
+
+  function loadProgram(bytes: string) {
+    const progBuf = cpu.progBytes;
+    for (let i = 0; i < bytes.length; i += 2) {
+      progBuf[i / 2] = parseInt(bytes.substr(i, 2), 16);
+    }
+  }
+
+  it('should execute `JMP 0xb8` instruction', () => {
+    loadProgram('0c945c00');
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(0x5c);
+    expect(cpu.cycles).toEqual(3);
+  });
+
+  it('should execute `OUT 0x3f, r1` instruction', () => {
+    loadProgram('1fbe');
+    cpu.data[1] = 0x5a; // put the value 5a in r1
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(0x1);
+    expect(cpu.cycles).toEqual(1);
+    expect(cpu.data[0x5f]).toEqual(0x5a);
+  });
+
+  it('should execute `LDI r28, 0xff` instruction', () => {
+    loadProgram('cfef');
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(0x1);
+    expect(cpu.cycles).toEqual(1);
+    expect(cpu.data[28]).toEqual(0xff);
+  });
+
+  it('should execute `RJMP 2` instruction', () => {
+    loadProgram('01c0');
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(2);
+    expect(cpu.cycles).toEqual(2);
+  });
+
+  it('should execute `ST X+, r1` instruction', () => {
+    loadProgram('1d92');
+    cpu.data[1] = 0x5a; // put the value 5a in r1
+    cpu.data[26] = 0x9a; // X <- 0x19
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(1);
+    expect(cpu.cycles).toEqual(1);
+    expect(cpu.data[0x9a]).toEqual(0x5a);
+    expect(cpu.data[26]).toEqual(0x9b); // verify that X was incremented
+  });
+
+  it('should execute `CPI r26, 0x9` instruction', () => {
+    loadProgram('a930');
+    cpu.data[26] = 0x8;
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(1);
+    expect(cpu.cycles).toEqual(1);
+    expect(cpu.data[95]).toEqual(53); // SREG 00110101 - HSNC
+  });
+
+  it('should execute `CPC r27, r18` instruction', () => {
+    loadProgram('b207');
+    cpu.data[18] = 0x1;
+    cpu.data[27] = 0x1;
+    avrInstruction(cpu);
+    expect(cpu.pc).toEqual(1);
+    expect(cpu.cycles).toEqual(1);
+    expect(cpu.data[95]).toEqual(0); // SREG 00000000
+  });
+});
diff --git a/src/instruction.ts b/src/instruction.ts
new file mode 100644
index 0000000..2b56def
--- /dev/null
+++ b/src/instruction.ts
@@ -0,0 +1,501 @@
+import { ICPU } from './cpu';
+
+export function avrInstruction(cpu: ICPU) {
+  const opcode = cpu.progMem[cpu.pc];
+
+  /* ADC */
+  if ((opcode & 0xfc00) === 0x1c00) {
+    /* not implemented */
+  }
+
+  /* ADD */
+  if ((opcode & 0xfc00) === 0xc00) {
+    /* not implemented */
+  }
+
+  /* ADIW */
+  if ((opcode & 0xff00) === 0x9600) {
+    /* not implemented */
+  }
+
+  /* AND */
+  if ((opcode & 0xfc00) === 0x2000) {
+    /* not implemented */
+  }
+
+  /* ANDI */
+  if ((opcode & 0xf000) === 0x7000) {
+    /* not implemented */
+  }
+
+  /* ASR */
+  if ((opcode & 0xfe0f) === 0x9405) {
+    /* not implemented */
+  }
+
+  /* BCLR */
+  if ((opcode & 0xff8f) === 0x9488) {
+    /* not implemented */
+  }
+
+  /* BLD */
+  if ((opcode & 0xfe08) === 0xf800) {
+    /* not implemented */
+  }
+
+  /* BRBC */
+  if ((opcode & 0xfc00) === 0xf400) {
+    /* not implemented */
+  }
+
+  /* BRBS */
+  if ((opcode & 0xfc00) === 0xf000) {
+    /* not implemented */
+  }
+
+  /* BSET */
+  if ((opcode & 0xff8f) === 0x9408) {
+    /* not implemented */
+  }
+
+  /* BST */
+  if ((opcode & 0xfe08) === 0xfa00) {
+    /* not implemented */
+  }
+
+  /* CALL */
+  if ((opcode & 0xfe0e) === 0x940e) {
+    /* not implemented */
+  }
+
+  /* CBI */
+  if ((opcode & 0xff00) === 0x9800) {
+    /* not implemented */
+  }
+
+  /* COM */
+  if ((opcode & 0xfe0f) === 0x9400) {
+    /* not implemented */
+  }
+
+  /* CP */
+  if ((opcode & 0xfc00) === 0x1400) {
+    /* not implemented */
+  }
+
+  /* CPC */
+  if ((opcode & 0xfc00) === 0x400) {
+    const arg1 = cpu.data[(opcode & 0x1f0) >> 4];
+    const arg2 = cpu.data[(opcode & 0xf) | ((opcode & 0x200) >> 5)];
+    let sreg = cpu.data[95];
+    const r = arg1 - arg2 - (sreg & 1);
+    sreg = (sreg & 0xfd) | (0 === r && (sreg >> 1) & 1 ? 2 : 0);
+    sreg = (sreg & 0xfb) | (128 & r ? 4 : 0);
+    sreg = (sreg & 0xf7) | ((arg1 ^ arg2) & (arg1 ^ r) & 128 ? 8 : 0);
+    sreg = (sreg & 0xef) | (((sreg >> 2) & 1) ^ ((sreg >> 3) & 1) ? 0x10 : 0);
+    sreg = (sreg & 0xfe) | (arg2 + (sreg & 1) > arg1 ? 1 : 0);
+    sreg = (sreg & 0xdf) | (1 & ((~arg1 & arg2) | (arg2 & r) | (r & ~arg1)) ? 0x20 : 0);
+    cpu.data[95] = sreg;
+  }
+
+  /* CPI */
+  if ((opcode & 0xf000) === 0x3000) {
+    const arg1 = cpu.data[((opcode & 0xf0) >> 4) + 16];
+    const arg2 = (opcode & 0xf) | ((opcode & 0xf00) >> 4);
+    const r = arg1 - arg2;
+    let sreg = cpu.data[95];
+    sreg = (sreg & 0xfd) | (0 === r ? 2 : 0);
+    sreg = (sreg & 0xfb) | (128 & r ? 4 : 0);
+    sreg = (sreg & 0xf7) | ((arg1 ^ arg2) & (arg1 ^ r) & 128 ? 8 : 0);
+    sreg = (sreg & 0xef) | (((sreg >> 2) & 1) ^ ((sreg >> 3) & 1) ? 0x10 : 0);
+    sreg = (sreg & 0xfe) | (arg2 > arg1 ? 1 : 0);
+    sreg = (sreg & 0xdf) | (1 & ((~arg1 & arg2) | (arg2 & r) | (r & ~arg1)) ? 0x20 : 0);
+    cpu.data[95] = sreg;
+  }
+
+  /* CPSE */
+  if ((opcode & 0xfc00) === 0x1000) {
+    /* not implemented */
+  }
+
+  /* DEC */
+  if ((opcode & 0xfe0f) === 0x940a) {
+    /* not implemented */
+  }
+
+  /* EOR */
+  if ((opcode & 0xfc00) === 0x2400) {
+    /* not implemented */
+  }
+
+  /* FMUL */
+  if ((opcode & 0xff88) === 0x308) {
+    /* not implemented */
+  }
+
+  /* FMULS */
+  if ((opcode & 0xff88) === 0x380) {
+    /* not implemented */
+  }
+
+  /* FMULSU */
+  if ((opcode & 0xff88) === 0x388) {
+    /* not implemented */
+  }
+
+  /* ICALL */
+  if (opcode === 0x9509) {
+    /* not implemented */
+  }
+
+  /* IJMP */
+  if (opcode === 0x9409) {
+    /* not implemented */
+  }
+
+  /* IN */
+  if ((opcode & 0xf800) === 0xb000) {
+    /* not implemented */
+  }
+
+  /* INC */
+  if ((opcode & 0xfe0f) === 0x9403) {
+    /* not implemented */
+  }
+
+  /* JMP */
+  if ((opcode & 0xfe0e) === 0x940c) {
+    cpu.pc = (cpu.progMem[cpu.pc + 1] | ((opcode & 1) << 16) | ((opcode & 0x1f0) << 13)) - 1;
+    cpu.cycles += 2;
+  }
+
+  /* LAC */
+  if ((opcode & 0xfe0f) === 0x9206) {
+    /* not implemented */
+  }
+
+  /* LAS */
+  if ((opcode & 0xfe0f) === 0x9205) {
+    /* not implemented */
+  }
+
+  /* LAT */
+  if ((opcode & 0xfe0f) === 0x9207) {
+    /* not implemented */
+  }
+
+  /* LDI */
+  if ((opcode & 0xf000) === 0xe000) {
+    cpu.data[((opcode & 0xf0) >> 4) + 16] = (opcode & 0xf) | ((opcode & 0xf00) >> 4);
+  }
+
+  /* LDS */
+  if ((opcode & 0xfe0f) === 0x9000) {
+    /* not implemented */
+  }
+
+  /* LDX */
+  if ((opcode & 0xfe0f) === 0x900c) {
+    /* not implemented */
+  }
+
+  /* LDX */
+  if ((opcode & 0xfe0f) === 0x900d) {
+    /* not implemented */
+  }
+
+  /* LDX */
+  if ((opcode & 0xfe0f) === 0x900e) {
+    /* not implemented */
+  }
+
+  /* LDY */
+  if ((opcode & 0xfe0f) === 0x8008) {
+    /* not implemented */
+  }
+
+  /* LDY */
+  if ((opcode & 0xfe0f) === 0x9009) {
+    /* not implemented */
+  }
+
+  /* LDY */
+  if ((opcode & 0xfe0f) === 0x900a) {
+    /* not implemented */
+  }
+
+  /* LDY */
+  if ((opcode & 0xd208) === 0x8008) {
+    /* not implemented */
+  }
+
+  /* LDZ */
+  if ((opcode & 0xfe0f) === 0x8000) {
+    /* not implemented */
+  }
+
+  /* LDZ */
+  if ((opcode & 0xfe0f) === 0x9001) {
+    /* not implemented */
+  }
+
+  /* LDZ */
+  if ((opcode & 0xfe0f) === 0x9002) {
+    /* not implemented */
+  }
+
+  /* LDZ */
+  if ((opcode & 0xd208) === 0x8000) {
+    /* not implemented */
+  }
+
+  /* LPM */
+  if (opcode === 0x95c8) {
+    /* not implemented */
+  }
+
+  /* LPM */
+  if ((opcode & 0xfe0f) === 0x9004) {
+    /* not implemented */
+  }
+
+  /* LPM */
+  if ((opcode & 0xfe0f) === 0x9005) {
+    /* not implemented */
+  }
+
+  /* LSR */
+  if ((opcode & 0xfe0f) === 0x9406) {
+    /* not implemented */
+  }
+
+  /* MOV */
+  if ((opcode & 0xfc00) === 0x2c00) {
+    /* not implemented */
+  }
+
+  /* MOVW */
+  if ((opcode & 0xff00) === 0x100) {
+    /* not implemented */
+  }
+
+  /* MUL */
+  if ((opcode & 0xfc00) === 0x9c00) {
+    /* not implemented */
+  }
+
+  /* MULS */
+  if ((opcode & 0xff00) === 0x200) {
+    /* not implemented */
+  }
+
+  /* MULSU */
+  if ((opcode & 0xff88) === 0x300) {
+    /* not implemented */
+  }
+
+  /* NEG */
+  if ((opcode & 0xfe0f) === 0x9401) {
+    /* not implemented */
+  }
+
+  /* NOP */
+  if (opcode === 0) {
+    /* NOP */
+  }
+
+  /* OR */
+  if ((opcode & 0xfc00) === 0x2800) {
+    /* not implemented */
+  }
+
+  /* SBR */
+  if ((opcode & 0xf000) === 0x6000) {
+    /* not implemented */
+  }
+
+  /* OUT */
+  if ((opcode & 0xf800) === 0xb800) {
+    cpu.writeData(((opcode & 0xf) | ((opcode & 0x600) >> 5)) + 32, cpu.data[(opcode & 0x1f0) >> 4]);
+  }
+
+  /* POP */
+  if ((opcode & 0xfe0f) === 0x900f) {
+    /* not implemented */
+  }
+
+  /* PUSH */
+  if ((opcode & 0xfe0f) === 0x920f) {
+    /* not implemented */
+  }
+
+  /* RCALL */
+  if ((opcode & 0xf000) === 0xd000) {
+    /* not implemented */
+  }
+
+  /* RET */
+  if (opcode === 0x9508) {
+    /* not implemented */
+  }
+
+  /* RETI */
+  if (opcode === 0x9518) {
+    /* not implemented */
+  }
+
+  /* RJMP */
+  if ((opcode & 0xf000) === 0xc000) {
+    cpu.pc = cpu.pc + ((opcode & 0x7ff) - (opcode & 0x800 ? 0x800 : 0));
+    cpu.cycles++;
+  }
+
+  /* ROR */
+  if ((opcode & 0xfe0f) === 0x9407) {
+    /* not implemented */
+  }
+
+  /* SBC */
+  if ((opcode & 0xfc00) === 0x800) {
+    /* not implemented */
+  }
+
+  /* SBCI */
+  if ((opcode & 0xf000) === 0x4000) {
+    /* not implemented */
+  }
+
+  /* SBI */
+  if ((opcode & 0xff00) === 0x9a00) {
+    /* not implemented */
+  }
+
+  /* SBIC */
+  if ((opcode & 0xff00) === 0x9900) {
+    /* not implemented */
+  }
+
+  /* SBIS */
+  if ((opcode & 0xff00) === 0x9b00) {
+    /* not implemented */
+  }
+
+  /* SBIW */
+  if ((opcode & 0xff00) === 0x9700) {
+    /* not implemented */
+  }
+
+  /* SBRC */
+  if ((opcode & 0xfe08) === 0xfc00) {
+    /* not implemented */
+  }
+
+  /* SBRS */
+  if ((opcode & 0xfe08) === 0xfe00) {
+    /* not implemented */
+  }
+
+  /* SLEEP */
+  if (opcode === 0x9588) {
+    /* not implemented */
+  }
+
+  /* SPM */
+  if (opcode === 0x95e8) {
+    /* not implemented */
+  }
+
+  /* SPM */
+  if (opcode === 0x95f8) {
+    /* not implemented */
+  }
+
+  /* STS */
+  if ((opcode & 0xfe0f) === 0x9200) {
+    /* not implemented */
+  }
+
+  /* STX */
+  if ((opcode & 0xfe0f) === 0x920c) {
+    /* not implemented */
+  }
+
+  /* STX */
+  if ((opcode & 0xfe0f) === 0x920d) {
+    cpu.writeData(cpu.dataView.getUint16(26, true), cpu.data[(opcode & 0x1f0) >> 4]);
+    cpu.dataView.setUint16(26, cpu.dataView.getUint16(26, true) + 1, true);
+  }
+
+  /* STX */
+  if ((opcode & 0xfe0f) === 0x920e) {
+    /* not implemented */
+  }
+
+  /* STY */
+  if ((opcode & 0xfe0f) === 0x8208) {
+    /* not implemented */
+  }
+
+  /* STY */
+  if ((opcode & 0xfe0f) === 0x9209) {
+    /* not implemented */
+  }
+
+  /* STY */
+  if ((opcode & 0xfe0f) === 0x920a) {
+    /* not implemented */
+  }
+
+  /* STY */
+  if ((opcode & 0xd208) === 0x8208) {
+    /* not implemented */
+  }
+
+  /* STZ */
+  if ((opcode & 0xfe0f) === 0x8200) {
+    /* not implemented */
+  }
+
+  /* STZ */
+  if ((opcode & 0xfe0f) === 0x9201) {
+    /* not implemented */
+  }
+
+  /* STZ */
+  if ((opcode & 0xfe0f) === 0x9202) {
+    /* not implemented */
+  }
+
+  /* STZ */
+  if ((opcode & 0xd208) === 0x8200) {
+    /* not implemented */
+  }
+
+  /* SUB */
+  if ((opcode & 0xfc00) === 0x1800) {
+    /* not implemented */
+  }
+
+  /* SUBI */
+  if ((opcode & 0xf000) === 0x5000) {
+    /* not implemented */
+  }
+
+  /* SWAP */
+  if ((opcode & 0xfe0f) === 0x9402) {
+    /* not implemented */
+  }
+
+  /* WDR */
+  if (opcode === 0x95a8) {
+    /* not implemented */
+  }
+
+  /* XCH */
+  if ((opcode & 0xfe0f) === 0x9204) {
+    /* not implemented */
+  }
+
+  cpu.pc = (cpu.pc + 1) % cpu.progMem.length;
+  cpu.cycles++;
+}
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..8a13fe6
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,2 @@
+export type u8 = number;
+export type u16 = number;