23 lines
563 B
Plaintext
23 lines
563 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: projects/02/FullAdder.hdl
|
|
|
|
/**
|
|
* Computes the sum of three bits.
|
|
*/
|
|
|
|
CHIP FullAdder {
|
|
IN a, b, c; // 1-bit inputs
|
|
OUT sum, // Right bit of a + b + c
|
|
carry; // Left bit of a + b + c
|
|
|
|
PARTS:
|
|
HalfAdder(a=b, b=c, sum=is, carry=ic);
|
|
Not(in=is, out=nis);
|
|
Mux(a=is, b=nis, sel=a, out=sum);
|
|
|
|
Or(a=is, b=ic, out=carryifaisone);
|
|
Mux(a=ic, b=carryifaisone, sel=a, out=carry);
|
|
}
|