nes-emu/apu/registers/APUStatus.js

A NES emulator

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _registers = require("../../registers");
/** Returns the current status of the APU. */
class APUStatus extends _registers.InMemoryRegister {
  constructor() {
    super();
    this.addField("lcPulse1", 0).addField("lcPulse2", 1).addField("lcTriangle", 2).addField("lcNoise", 3).addField("remainingBytesDMC", 4).addField("frameIRQFlag", 6).addField("dmcIRQFlag", 7);
  }

  /** Reads the status and resets the frame IRQ flag. */
  readAt() {
    const {
      apu
    } = this.context;
    const channels = apu.channels;
    this.lcPulse1 = +(channels.pulses[0].lengthCounter.counter > 0);
    this.lcPulse2 = +(channels.pulses[1].lengthCounter.counter > 0);
    this.lcTriangle = +(channels.triangle.lengthCounter.counter > 0);
    this.lcNoise = +(channels.noise.lengthCounter.counter > 0);
    this.remainingBytesDMC = channels.dmc.remainingBytes > 0;
    this.frameIRQFlag = apu.frameIRQFlag;
    this.dmcIRQFlag = apu.registers.dmc.control.irqEnable;
    if (!this.context.isDebugging) apu.frameIRQFlag = false;
    return this.value;
  }
}
exports.default = APUStatus;