// 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/PC.hdl

/**
 * A 16-bit counter with load and reset control bits.
 * if      (reset[t] == 1) out[t+1] = 0
 * else if (load[t] == 1)  out[t+1] = in[t]
 * else if (inc[t] == 1)   out[t+1] = out[t] + 1  (integer addition)
 * else                    out[t+1] = out[t]
 */

CHIP PC {
    IN in[16],load,inc,reset;
    OUT out[16];


    PARTS:

    //Inc, Rückkopplung des out und +1
    Inc16(in=toinc, out=outinc);

    //inc-flag
    Mux16(a=outtomux, b=outinc, sel=inc, out=outmuxinc);
    //load-flag, wenn 1 dann schiebe in auf das in des Registers
    Mux16(a=outmuxinc, b=in, sel=load, out=outmuxload);
    //reset-flag
    Mux16(a=outmuxload, b=false, sel=reset, out=outmuxreset);
    //Register
    Register(in=outmuxreset, load=true, out=out, out=toinc, out=outtomux);
}