8-Bit Ripple Carry Adder

What is a Ripple Carry Adder?

A ripple carry adder is a digital circuit that produces the arithmetic sum of two binary numbers. It. can be constructed with full adders connected in cascaded with the carry output from each full adder connected to the carry input of the next full adder in the chain. This kind of adder is called Ripple Carry Adder, since each carry bit "ripples" to the next full adder.

Here is a top level view of a 4-bit Ripple Carry Adder for reference :

Truth Table of Full Adder

Truth Table of Half Adder

8-bit RCA Netlist View

Top Level RTL View

Gate Level Synthesis

Technology Viewer

Delay Calculation

The layout of ripple carry adder is simple, which allows for fast design time; however, the ripple carry adder is relatively slow, since each full adder must wait for the carry bit to be calculated from the previous full adder. The gate delay can easily be calculated by inspection of the full adder circuit. Total time taken for the 8bit Ripple Carry Adder is :

T_RCA = N * T_FA
where, T_FA = Propogation Delay of each Full Adder Circuit

Simulation Waveform - Modelsim Altera

Pin Planner - Intel Quartus Prime

Board Used - Intel MAX10 FPGA - 10M50DAF484C7G

This project was submitted for the final project of the course Computer Aided Digital Design (UE22EC252A) by Sahil S Prabhu.