Full adder

A project log for ALU in DCTL technology

A full ALU, capable of ADD, SUB and all logic functions, with only 12 transistors

roelhroelh 08/04/2018 at 20:220 Comments

The Falstad simulation of the full adder has two parts. The first part creates the input signals for the adder:

There are switches to change the input signals A and B, and the Carry input signal. There are also 3 LED's to check the input values. At the left side you see the 3 created signals CY-IN, A and B, and an inverted version from B.

The second part is the actual adder:

This is actually an implementation of a classic adder design.  The following picture shows the function of the transistors: