RAM512.hdl

// This file is part of the materials accompanying the book
// "The Elements of Computing Systems" by Nisan and Schocken,
// MIT Press. Book site: www.idc.ac.il/tecs
// File name: projects/03/b/RAM512.hdl

/**
 * Memory of 512 registers, each 16 bit-wide. Out holds the value
 * stored at the memory location specified by address. If load==1, then
 * the in value is loaded into the memory location specified by address
 * (the loaded value will be emitted to out from the next time step onward).
 */

CHIP RAM512 {
    IN in[16], load, address[9];
    OUT out[16];

    PARTS:
    RAM64(in=in, load=loadA, address=address[0..5], out=ramA);
    RAM64(in=in, load=loadB, address=address[0..5], out=ramB);
    RAM64(in=in, load=loadC, address=address[0..5], out=ramC);
    RAM64(in=in, load=loadD, address=address[0..5], out=ramD);
    RAM64(in=in, load=loadE, address=address[0..5], out=ramE);
    RAM64(in=in, load=loadF, address=address[0..5], out=ramF);
    RAM64(in=in, load=loadG, address=address[0..5], out=ramG);
    RAM64(in=in, load=loadH, address=address[0..5], out=ramH);
    DMux8Way(in=load, sel=address[6..8], a=loadA, b=loadB, c=loadC, d=loadD, e=loadE, f=loadF, g=loadG, h=loadH);
    Mux8Way16(a=ramA, b=ramB, c=ramC, d=ramD, e=ramE, f=ramF, g=ramG, h=ramH, sel=address[6..8], out=out);
}