/2/ZN.hdl

 1CHIP ZN {
 2    IN  in[16], z, n;
 3    OUT out[16];
 4
 5    PARTS:
 6    // first decide whether to zero input
 7    Mux16(a=in, b=false, sel=z, out=zout);
 8
 9    // then decide whether to negate possibly zeroed input
10    Not16(in=zout, out=notzout);
11    Mux16(a=zout, b=notzout, sel=n, out=out);
12}