Logic Gates

Topics: Logic gate, Addition, XOR gate Pages: 3 (754 words) Published: May 31, 2013

September 18th, 2007 CSC343 Fall 2007 Prepared by: Steven Medina

PURPOSE

A half-adder (HA) is an adder that accepts two inputs and gives two outputs. The two inputs are the two single bit binary values that will be added to each other. The two outputs represent the sum. We need two outputs (rather than one output) because the sum may have a carry bit. For example, in binary, 1+0 = 1. This situation has no carry bit in the output. In other words, the output itself is 1 bit. However, if we add 1+1, we get 10. This output is 2 bits long. This is a case where the carry-bit for the output is needed. A half adder consists of two logic gates. These are an AND gate, and an Exclusive OR gate. A diagram of a half adder is shown below.

. Figure 1: Half Adder using XOR and AND gate.

For the design of the half adder, do the following. 1) Create a new project in Quartus. Where it asks for the family or device you wish to target for compilation, select the Cyclone II board. Under the list of available devices, click EP2C35F672C6. 2) Design the half-adder shown in figure 1 in a...