Lab 4 - 4-bit Ripple-Carry Adder

In this lab, you will design a 4-bit ripple-carry adder with carry-in and carry-out. As we are deigning larger circuits, you will face many new challenges. While designing a 4-bit adder is not complex with regards to a typically design, this lab will introduce the concept of designing and testing a circuit modularly. Instead of creating the full schematic and layout for the 4-bit adder, you will first design a 1-bit adder slice. After successfully implementing and testing the 1-bit adder, you will design the full 4-bit adder.

Note: Be careful with your initial pin placement for your 1-bit adder, as you will need to route wires between adder slices.

Lab Procedure

The following provides the steps that you must follow to complete this lab.

1. Design and test transistor schematic for 1-bit adder.
2. Design and test layout for 1-bit adder.
3. Design and test transistor schematic for 4-bit adder.

Hint: In designing the schematic for your 4-bit adder, you may want to create a symbol for you're 1-bit adder, and connect four 1-bit adders together.

Demo

You must demo the following aspects or your 4-bit adder design to the TA.

1. 1-bit adder layout design and extracted layout simulation.
2. 4-bit adder schematic design and simulation.

Lab Report

In addition to the standard lab report format, you must submit the following information.

1. 1-bit adder transistor schematic.
2. 1-bit adder layout.
3. 1-bit adder extracted layout simulation.
4. 4-bit adder transistor schematic.
5. 4-bit adder simulation.