hdl-js/dist/emulator/hardware/builtin-gates/Mux4Way16.js

Hardware definition language (HDL) and Hardware simulator

/**
 * The MIT License (MIT)
 * Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
 */

'use strict';

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var BuiltInGate = require('../BuiltInGate');

var _require = require('../../../util/numbers'),
    int16Table = _require.int16Table;

/**
 * Canonical truth table for the `Mux4Way16` gate.
 */


var TRUTH_TABLE = int16Table([{
  a: 0,
  b: 0,
  c: 0,
  d: 0,
  sel: 0,
  out: 0
}, {
  a: 0,
  b: 0,
  c: 0,
  d: 0,
  sel: 1,
  out: 0
}, {
  a: 0,
  b: 0,
  c: 0,
  d: 0,
  sel: 2,
  out: 0
}, {
  a: 0,
  b: 0,
  c: 0,
  d: 0,
  sel: 3,
  out: 0
}, {
  a: 4660,
  b: 39030,
  c: 43690,
  d: 21845,
  sel: 0,
  out: 4660
}, {
  a: 4660,
  b: 39030,
  c: 43690,
  d: 21845,
  sel: 1,
  out: 39030
}, {
  a: 4660,
  b: 39030,
  c: 43690,
  d: 21845,
  sel: 2,
  out: 43690
}, {
  a: 4660,
  b: 39030,
  c: 43690,
  d: 21845,
  sel: 3,
  out: 21845
}]);

/**
 * 4-way 16-bit multiplexor.
 * The two sel[0..1] bits select the output to be one of the four input buses:
 * (0->a ... 3->d).
 */

var Mux4Way16 = function (_BuiltInGate) {
  _inherits(Mux4Way16, _BuiltInGate);

  function Mux4Way16() {
    _classCallCheck(this, Mux4Way16);

    return _possibleConstructorReturn(this, (Mux4Way16.__proto__ || Object.getPrototypeOf(Mux4Way16)).apply(this, arguments));
  }

  _createClass(Mux4Way16, [{
    key: 'eval',

    /**
     * IN a[16], b[16], c[16], d[16], sel[2];
     * OUT out[16];
     *
     * Abstract:
     *
     *   Mux16(a=a, b=b, sel=sel[0], out=ab);
     *   Mux16(a=c, b=d, sel=sel[0], out=cd);
     *   Mux16(a=ab, b=cd, sel=sel[1], out=out);
     */
    value: function _eval() {
      var a = this.getInputPins()[0].getValue();
      var b = this.getInputPins()[1].getValue();
      var c = this.getInputPins()[2].getValue();
      var d = this.getInputPins()[3].getValue();

      var sel = this.getInputPins()[4].getValue();

      var out = 0;

      switch (sel) {
        case 0:
          out = a;
          break;
        case 1:
          out = b;
          break;
        case 2:
          out = c;
          break;
        case 3:
          out = d;
          break;
      }

      this.getOutputPins()[0].setValue(out);
    }
  }]);

  return Mux4Way16;
}(BuiltInGate);

/**
 * Specification of the `Mux4Way16` gate.
 */


Mux4Way16.Spec = {
  name: 'Mux4Way16',

  description: ['4-way 16-bit multiplexor gate.', '', 'The two sel[0..1] bits select the output to be one ', 'of the four input buses: (0->a ... 3->d).'].join('\n'),

  inputPins: [
  // Data pins.
  { name: 'a', size: 16 }, { name: 'b', size: 16 }, { name: 'c', size: 16 }, { name: 'd', size: 16 },

  // Selector.
  { name: 'sel', size: 2 }],

  outputPins: [{ name: 'out', size: 16 }],

  truthTable: TRUTH_TABLE
};

module.exports = Mux4Way16;