nand2tetris/projects/03/a/RAM8.hdl

// This file is part of www.nand2tetris.org
// and the book "The Elements of Computing Systems"
// by Nisan and Schocken, MIT Press.
// File name: projects/03/a/RAM8.hdl

/**
 * Memory of 8 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 RAM8 {
    IN in[16], load, address[3];
    OUT out[16];

    PARTS:
    // Put your code here:
    DMux8Way(in=load, sel=address, a=toRegisterA,
                                   b=toRegisterB,
                                   c=toRegisterC,
                                   d=toRegisterD,
                                   e=toRegisterE,
                                   f=toRegisterF,
                                   g=toRegisterG,
                                   h=toRegisterH);

    Register(in=in, load=toRegisterA, out=fromRegisterA);
    Register(in=in, load=toRegisterB, out=fromRegisterB);
    Register(in=in, load=toRegisterC, out=fromRegisterC);
    Register(in=in, load=toRegisterD, out=fromRegisterD);
    Register(in=in, load=toRegisterE, out=fromRegisterE);
    Register(in=in, load=toRegisterF, out=fromRegisterF);
    Register(in=in, load=toRegisterG, out=fromRegisterG);
    Register(in=in, load=toRegisterH, out=fromRegisterH);

    Mux8Way16(sel=address, out=out, a=fromRegisterA,
                                    b=fromRegisterB,
                                    c=fromRegisterC,
                                    d=fromRegisterD,
                                    e=fromRegisterE,
                                    f=fromRegisterF,
                                    g=fromRegisterG,
                                    h=fromRegisterH);
}