24 lines
653 B
Plaintext
24 lines
653 B
Plaintext
// 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;
|
|
}
|