4 Bit Adder Circuit. It s only used if you are combining several adders. The main objectives of the project is to minimize the total delay of the adder i e.
The c out pin is the output for the 5th bit of the sum s or the carry out bit. The c in pin is the input for a carry in bit. 3 introduction the topic of the course project is to design a 4 bit adder in the standard 0 25 um cmos technology.
A0 a1 a2 a3 for a b0 b1 b2 b3 for b.
Which are the 2 sets of 4 bits to be added so in the design it is more efficient in terms of delay area and power to design a half bit adder for the first bit adder as there is no carry in bit for the. Simplified schematics of the 4 bit serial adder with parallel load. Lets consider two 4 bit binary numbers a and b as inputs to the digital circuit for the operation with digits. A simplified schematics of the circuit is shown below.
