// 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:
	DMux8Way(in=load, sel=address[6..8], a=l0, b=l1, c=l2, d=l3, e=l4, f=l5, g=l6, h=l7);
	RAM64(in=in, load=l0, address=address[0..5], out=o0);
	RAM64(in=in, load=l1, address=address[0..5], out=o1);
	RAM64(in=in, load=l2, address=address[0..5], out=o2);
	RAM64(in=in, load=l3, address=address[0..5], out=o3);
	RAM64(in=in, load=l4, address=address[0..5], out=o4);
	RAM64(in=in, load=l5, address=address[0..5], out=o5);
	RAM64(in=in, load=l6, address=address[0..5], out=o6);
	RAM64(in=in, load=l7, address=address[0..5], out=o7);
	Mux8Way16(a=o0, b=o1, c=o2, d=o3, e=o4, f=o5, g=o6, h=o7, sel=address[6..8], out=out);
}