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

/**
 * A 16-bit counter with increment, load, and reset modes.
 * if      (inc(t) == 1)   out(t+1) = out(t) + 1
 * else if (load(t) == 1)  out(t+1) = in(t)
 * else if (reset(t) == 1) out(t+1) = 0
 * else                    out(t+1) = out(t).
 *
 * To select a mode, assert the relevant control bit,
 * and de-assert the other two bits. 
 */
CHIP PC {

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

    BUILTIN PC;
    CLOCKED in, load, inc, reset;
}