/**
 * 4-way 16-bit multiplexor:
 * out = a if sel == 00
 *       b if sel == 01
 *       c if sel == 10
 *       d if sel == 11
 */

CHIP Mux4Way16 {
    IN a[16], b[16], c[16], d[16], sel[2];
    OUT out[16];

    PARTS:
    Mux16(a=a,b=b,sel=sel[0],out=o1);
   	Mux16(a=c,b=d,sel=sel[0],out=o2);
	Mux16(a=o1,b=o2,sel=sel[1],out=out);
}