ALU: 1-bit

We now have the ingredients for a simple 1-bit arithmetic-logic unit (ALU)

Operations:

ADD

a + b + cin

AND

a AND b

OR

a OR b

Inputs:

data:

a, b, cin

control:

con1, con2

Outputs:

result, cout

Components:

AND gate

OR gate

Full adder

4-1 MUX

1-bit ALU (Fig. 4.14)

(Operation is 2-bit control con1, con2)

Can construct k-bit ALU by combining k 1-bit ALUs

What other operations could we have?