Source

modules/PriorityEncoder.js

import CircuitElement from "../circuitElement";
import Node, { findNode, dec2bin } from "../node";
import simulationArea from "../simulationArea";
import { correctWidth, rect, fillText } from "../canvasApi";
/**
 * @class
 * PriorityEncoder
 * @extends CircuitElement
 * @param {number} x - x coordinate of element.
 * @param {number} y - y coordinate of element.
 * @param {Scope=} scope - Cirucit on which element is drawn
 * @param {string=} dir - direction of element
 * @param {number=} bitWidth - bit width per node.
 * @category modules
 */
import { colors } from "../themer/themer";

export default class PriorityEncoder extends CircuitElement {
    constructor(x, y, scope = globalScope, dir = "RIGHT", bitWidth = 1) {
        super(x, y, scope, dir, bitWidth);
        /* this is done in this.baseSetup() now
        this.scope['PriorityEncoder'].push(this);
        */
        this.bitWidth = bitWidth || parseInt(prompt("Enter bitWidth"), 10);
        this.inputSize = 1 << this.bitWidth;

        this.yOff = 1;
        if (this.bitWidth <= 3) {
            this.yOff = 2;
        }

        this.setDimensions(20, this.yOff * 5 * this.inputSize + 10);
        this.rightDimensionX += 10;
        this.directionFixed = true;
        this.rectangleObject = false;

        this.inp1 = [];
        for (let i = 0; i < this.inputSize; i++) {
            const a = new Node(
                -10,
                +this.yOff * 10 * (i - this.inputSize / 2) + 10,
                0,
                this,
                1
            );
            this.inp1.push(a);
        }

        this.output1 = [];
        for (let i = 0; i < this.bitWidth; i++) {
            const a = new Node(
                30,
                +2 * 10 * (i - this.bitWidth / 2) + 10,
                1,
                this,
                1
            );
            this.output1.push(a);
        }

        this.enable = new Node(
            10,
            20 + this.inp1[this.inputSize - 1].y,
            1,
            this,
            1
        );
    }

    /**
     * @memberof PriorityEncoder
     * fn to create save Json Data of object
     * @return {JSON}
     */
    customSave() {
        const data = {
            nodes: {
                inp1: this.inp1.map(findNode),
                output1: this.output1.map(findNode),
                enable: findNode(this.enable),
            },
            constructorParamaters: [this.direction, this.bitWidth],
        };
        return data;
    }

    /**
     * @memberof PriorityEncoder
     * function to change bitwidth of the element
     * @param {number} bitWidth - new bitwidth
     */
    newBitWidth(bitWidth) {
        if (bitWidth === undefined || bitWidth < 1 || bitWidth > 32) return;
        if (this.bitWidth === bitWidth) return;

        this.bitWidth = bitWidth;
        const obj = new PriorityEncoder(
            this.x,
            this.y,
            this.scope,
            this.direction,
            this.bitWidth
        );
        this.inputSize = 1 << bitWidth;

        this.cleanDelete();
        simulationArea.lastSelected = obj;
        return obj;
    }

    /**
     * @memberof PriorityEncoder
     * resolve output values based on inputData
     */
    resolve() {
        let out = 0;
        let temp = 0;
        for (let i = this.inputSize - 1; i >= 0; i--) {
            if (this.inp1[i].value === 1) {
                out = dec2bin(i);
                break;
            }
        }
        temp = out;

        if (out.length !== undefined) {
            this.enable.value = 1;
        } else {
            this.enable.value = 0;
        }
        simulationArea.simulationQueue.add(this.enable);

        if (temp.length === undefined) {
            temp = "0";
            for (let i = 0; i < this.bitWidth - 1; i++) {
                temp = `0${temp}`;
            }
        }

        if (temp.length !== this.bitWidth) {
            for (let i = temp.length; i < this.bitWidth; i++) {
                temp = `0${temp}`;
            }
        }

        for (let i = this.bitWidth - 1; i >= 0; i--) {
            this.output1[this.bitWidth - 1 - i].value = Number(temp[i]);
            simulationArea.simulationQueue.add(
                this.output1[this.bitWidth - 1 - i]
            );
        }

        this.setOutputsUpstream(true);
    }

    /**
     * @memberof PriorityEncoder
     * function to draw element
     */
    customDraw() {
        var ctx = simulationArea.context;
        ctx.beginPath();
        ctx.strokeStyle = colors["stroke"];
        ctx.fillStyle = colors["fill"];
        ctx.lineWidth = correctWidth(3);
        const xx = this.x;
        const yy = this.y;
        if (this.bitWidth <= 3) {
            rect(
                ctx,
                xx - 10,
                yy - 10 - this.yOff * 5 * this.inputSize,
                40,
                20 * (this.inputSize + 1)
            );
        } else {
            rect(
                ctx,
                xx - 10,
                yy - 10 - this.yOff * 5 * this.inputSize,
                40,
                10 * (this.inputSize + 3)
            );
        }
        if (
            (this.hover && !simulationArea.shiftDown) ||
            simulationArea.lastSelected === this ||
            simulationArea.multipleObjectSelections.contains(this)
        )
            ctx.fillStyle = colors["hover_select"];
        ctx.fill();
        ctx.stroke();

        ctx.beginPath();
        ctx.fillStyle = "black";
        ctx.textAlign = "center";
        for (let i = 0; i < this.inputSize; i++) {
            fillText(ctx, String(i), xx, yy + this.inp1[i].y + 2, 10);
        }
        for (let i = 0; i < this.bitWidth; i++) {
            fillText(
                ctx,
                String(i),
                xx + this.output1[0].x - 10,
                yy + this.output1[i].y + 2,
                10
            );
        }
        fillText(ctx, "EN", xx + this.enable.x, yy + this.enable.y - 5, 10);
        ctx.fill();
    }

    verilogBaseType() {
        return this.verilogName() + this.inp1.length;
    }

    generateVerilog() {
        PriorityEncoder.selSizes.add(this.bitWidth);
        return CircuitElement.prototype.generateVerilog.call(this);
    }

    static moduleVerilog() {
        var output = "";
    
        for (var size of PriorityEncoder.selSizes) {
            var numInput = 1 << size;
            output += "\n";
            output += "module PriorityEncoder" + numInput;
            output += "(sel, ze, ";
            for (var j = 0; j < numInput-1; j++) {
                output += "in" + j + ", ";
            }
            output += "in" + (numInput-1) + ");\n";
    
            output += "  output reg [" + (size-1) + ":0] sel;\n";
            output += "  output reg ze;\n";
    
            output += "  input "
            for (var j = 0; j < numInput-1; j++) {
                output += "in" + j + ", ";
            }
            output += "in" + (numInput-1) + ";\n";
            output += "\n";
    
            output += "  always @ (*) begin\n";
            output += "    sel = 0;\n";
            output += "    ze = 0;\n";
            output += "    if (in" + (numInput-1) + ")\n";
            output += "      sel = " + (numInput-1) + ";\n";
            for (var j = numInput-2; j <= 0; j++) {
                output += "    else if (in" + j + ")\n";
                output += "      sel = " + j + ";\n";
            }
            output += "    else\n";
            output += "      ze = 1;\n"
            output += "  end\n";
            output += "endmodule\n";
        }
    
        return output;
    }

    //reset the sized before Verilog generation
    static resetVerilog() {
        PriorityEncoder.selSizes = new Set
    }
}

/**
 * @memberof PriorityEncoder
 * Help Tip
 * @type {string}
 * @category modules
 */
PriorityEncoder.prototype.tooltipText =
    "Priority Encoder ToolTip : Compresses binary inputs into a smaller number of outputs.";
PriorityEncoder.prototype.helplink =
    "https://docs.circuitverse.org/#/chapter4/5muxandplex?id=priority-encoder";
PriorityEncoder.prototype.objectType = "PriorityEncoder";