refactor: added peripherals and cpu feature folders

1 files changed, 78 insertions, 0 deletions

diff --git a/src/cpu/cpu.ts b/src/cpu/cpu.ts
new file mode 100644
index 0000000..93f79d0
--- /dev/null
+++ b/src/cpu/cpu.ts
@@ -0,0 +1,78 @@
+/**
+ * AVR 8 CPU data structures
+ * Part of AVR8js
+ *
+ * Copyright (C) 2019, Uri Shaked
+ */
+
+import { u16, u8 } from '../types';
+
+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;
+  pc: u16;
+  cycles: number;
+
+  readData(addr: u16): u8;
+  writeData(addr: u16, value: u8): void;
+}
+
+export type CPUMemoryHook = (value: u8, oldValue: u8, addr: u16) => boolean | void;
+export interface CPUMemoryHooks {
+  [key: number]: CPUMemoryHook;
+}
+
+export class CPU implements ICPU {
+  readonly data: Uint8Array = new Uint8Array(this.sramBytes + registerSpace);
+  readonly data16 = new Uint16Array(this.data.buffer);
+  readonly dataView = new DataView(this.data.buffer);
+  readonly progBytes = new Uint8Array(this.progMem.buffer);
+  readonly writeHooks: CPUMemoryHooks = [];
+
+  pc = 0;
+  cycles = 0;
+
+  constructor(public progMem: Uint16Array, private sramBytes = 8192) {
+    this.reset();
+  }
+
+  reset() {
+    this.data.fill(0);
+    this.SP = this.data.length - 1;
+  }
+
+  readData(addr: number) {
+    return this.data[addr];
+  }
+
+  writeData(addr: number, value: number) {
+    const hook = this.writeHooks[addr];
+    if (hook) {
+      if (hook(value, this.data[addr], addr)) {
+        return;
+      }
+    }
+    this.data[addr] = value;
+  }
+
+  get SP() {
+    return this.dataView.getUint16(93, true);
+  }
+
+  set SP(value: number) {
+    this.dataView.setUint16(93, value, true);
+  }
+
+  get SREG() {
+    return this.data[95];
+  }
+
+  get interruptsEnabled() {
+    return this.SREG & 0x80 ? true : false;
+  }
+}