Lab 1: Quartus II Familiarization

I. Introduction

Altera Quartus is a  design software from Altera. Its features include:

• An implementation of VHDL and Verilog for hardware description.
• Visual edition of logic circuits.
• Vector waveform simulation.

Quartus II is a software tool produced by Altera for analysis and synthesis of VHDL designs, which enables the developer to compile their designs, perform timing analysis, examine RTL diagrams, simulate a design's reaction to different stimuli, and configure the target device with the programmer.

For more information, you may visit this site

II. Objective

To be able to create circuit design in Quartus II.

III.Conceptual Framework

1.Decoder

A decoder is a device which does the reverse of an encoder, undoing the encoding so that the original information can be retrieved. The same method used to encode is usually just reversed in order to decode. It is a combinational circuit that converts binary information from n input lines to a maximum of 2ⁿ unique output lines.

In digital electronics, a decoder can take the form of a multiple-input, multiple-output logic circuit that converts coded inputs into coded outputs, where the input and output codes are different. e.g. n-to-2ⁿ, binary-coded decimal decoders. Enable inputs must be on for the decoder to function, otherwise its outputs assume a single "disabled" output code word. Decoding is necessary in applications such as data multiplexing, 7 segment display and memory address decoding.

The example decoder circuit would be an AND gate because the output of an AND gate is "High" (1) only when all its inputs are "High." Such output is called as "active High output". If instead of AND gate, the NAND gate is connected the output will be "Low" (0) only when all its inputs are "High". Such output is called as "active low output".

 

2. Multiplexer

An electronics, a multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2ⁿ inputs has n select lines, which are used to select which input line to send to the output. Multiplexers are mainly used to increase the amount of data that can be sent over the network within a certain amount of time and bandwidth. A multiplexer is also called a data selector.

An electronic multiplexer makes it possible for several signals to share one device or resource, for example one A/D converter or one communication line, instead of having one device per input signal.

On the other hand, a demultiplexer (or demux) is a device taking a single input signal and selecting one of many data-output-lines, which is connected to the single input. A multiplexer is often used with a complementary demultiplexer on the receiving end.

An electronic multiplexer can be considered as a multiple-input, single-output switch, and a demultiplexer as a single-input, multiple-output switch. The schematic symbol for a multiplexer is an isosceles trapezoid with the longer parallel side containing the input pins and the short parallel side containing the output pin. The schematic on the right shows a 2-to-1 multiplexer on the left and an equivalent switch on the right. The sel wire connects the desired input to the output.

IV.Data and result

V. Analysis

 Quartus II  is a very useful and easy to use program. Since this was our first experiment, that's why we experienced different errors like the wrong assigning of pins and the wrong connection of wires to the right input of the Integrated Circuit.

VI. Conclusion

By using Quartus II, we were able to create logic circuits with decoder and multiplexer. Since we have took the Logic circuit last semester so we did not have any problem with the gates but there was some problems with the pins assignment . Hopefully we can improve our skill in next lab.