﻿ Digital Circuits and Systems - Circuits i Sistemes Digitals (CSD) - EETAC - UPC
 Bachelor's Degree in Telecommunications Systems and in Network Engineering

Q&A

## PLA9: On basic digital I/O. Designing a combinational circuit

PLA10

 NOTE: This post lab asssignmen must be solved only after having completed successfully lab session and studied example  because you will copy and adapt materials from it.

NOTE: EDA in use this semester: Proteus electrical simulator, Notepad++ editor, Microchip MPLABX and XC8 compiler.

Specifications: wind compass

We want to design a digital wind direction meter (wind_compass) based on a 16-position optoelectronic rotary encoder as shown in Fig. 1 using a PIC18F4520. This PLA is adapted from problem where you will find questions and ideas.

 Fig. 1. Circuit symbol and its realisation in Proteus wind_compass.pdsprj based on classic chips for better comprehending how does it work.

Fig. 2 represents the wind compass subdivided in 16 directions each of which is assigned to a 4-bit Gray code.

 Fig. 2. Wind compass describing the sixteen principal bearings used to measure wind direction and an example of commercial manufactured wind transducer.

Pin assignment:

D3 --> RA0; D2 --> RA1; D1 --> RA2; D0 --> RA3

Y(15..8) --> RB(7..0); Y(7..0) --> RD(7..0)

E --> RC7

S(6..0) --> RC(6..0)

Project location:

C:\CSD\P9\PLA9\wind\(files)

Specifications: BCD to 7-segments decoder

Design a BCD_7seg_decoder chip using a PIC18F4520. This PLA is adapted from problem where you will find questions and ideas.

 Fig.1. When operating, this decoder only deals with inputs from 0 to 9 ("0000" to "1001"). The remaining 6 combinations are of no interest. Fig.2. Truth table definition as an circuit.

Use the following pin connections:

D3 --> RA2; D2 --> RA3; D1 --> RA0; D0 --> RA1

a --> RB7; b --> RB6; c --> RC5; d --> RC4; e --> RD7; f --> RC1; g --> RC0

Project location:

C:\CSD\P9\PLA9\7seg\(files)

Specifications: 4-bit ones counter

Design the 4-bit ones counter represented in Fig. 1 using a PIC18F4520. This PLA is adapted from problem where you will find questions and ideas.

 Fig.1. Symbol and truth table.

Pin assigment:

D3 --> RC4; D2 --> RC3; D1 --> RB6; D0 --> RA1; Y2 --> RA2; Y1 --> RB5; Y0 --> RB0

Project location:

C:\CSD\P9\PLA9\Ones_counter\(files)

Specifications: 8-bit comparator

Design the 8-bit comparator represented in Fig. 1 using a PIC18F4520. This PLA is adapted from problem where you will find questions and ideas.

 Fig. 1. Comp_8bit symbol.

Project location:

C:\CSD\P9\PLA9\Comp\(files)

 Example of individual assignments Circuit Est. 1 wind compass Est. 2 BCD to 7-segments decoder Est. 3 4-bit ones counter Est. 4 8-bit comparator Est. 5 ··· ··· ··· ··· ··· ··· ···