pic micro presentation

8/6/2019 Pic Micro Presentation

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PIC Microcontroller

Prepared by:

Ahmed Usama


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References


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Group Formation

Group of 4 persons. Nominate a representative.


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MICROCONTROLLERS1st DAY


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MICROCONTROLLERS1st DAY

ReviewWhat is the embedded system

Microprocessor , Microcontroller and FPGA.

Why a microcontroller is needed?

Variety of microcontrollers.Why PIC microcontrollers?

Specificiations of PIC 16F877.

Programming PIC 16F877.

PIC 16F877 in circuit.Application.


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Review

Digital System:

A system that works with discrete elements of information ratherthan with continuous signals as in an analog system.

This discrete information is represented in binary form.

Data processing is carried out by means of binary logicelements using binary signals.

Quantities are stored in binary storage elements (memory).


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There are two primary classifications of logic circuits(System):

1. Combinational logic circuits

Circuits of this type have outputs that are functions of the inputs(illustrated below)

The order in which the inputs are applied is not important.

Combinational logic circuits have no capability for memory

Combinational

LogicInputs Outputs = f(Inputs)

Combinational Logic Circuit


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2. Sequential logic circuits

Circuits of this type have outputs that are functions of both inputsand previous outputs (illustrated below)

Sequential circuits contain some type of memory elements. As anexample, a counter must remember that its previous output was 6 inorder to produce its new output 7.

Combinational

Logic

Inputs Outputs = f(inputs + past outputs)

Memory

Sequential Logic Circuit


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Embedded System

An embedded system is a computer system designedto perform one or a few dedicated functions(often real-time).

Hardware and Software expected to function withouthuman intervention.

Respond, monitor, control external environment usingsensor and actuators.

In contrast a general-purpose computer, such as apersonal computer (PC), is designed to be flexible and to

meet a wide range of end-user needs.


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Why Embedded systems

Low cost. Small packaging.

Low power consumption.

Programmable, re-programmable.

Easy integration with circuit. For application in which cost, power and space are

critical

Single-purpose

Real-time operation.(ex: ABS (WSS) ; ECU(FI)) Application dependent processor.

Automation


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Automation

Control

Electronic circuits Power Electronics

Mechanics


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A microcontroller is a specialized form of microprocessor that is designed tobe self-sufficient and cost-effective, where a microprocessor is typicallydesigned to be general purpose (the kind used in a PC). Microcontrollersare frequently found in automobiles, office machines, toys, and appliances.

Microcontroller combines onto the same chip:

The CPU core (microprocessor),Memory (both ROM and RAM) ,Someparallel digital I/O

A microcontroller is part of an embedded system, which is essentially the(Microcontroller + whole circuit board) to perform dedicated task.

Microcontroller incorporates features of microprocessor(CPU,ALU,Register)

along with the presence of added features like RAM, ROM, I\O ports,counter etc.

A microcontroller controls the operation of machine using fixed programstored in Rom that doesn't change with lifetime


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What is the difference?

Microprocessor

Microcontrollers FPGA


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SO

Microcontrollers are intelligentelectronic devices used tocontroland monitordevices inthe real world

Microcontrollers areprogrammeddevices.

A program is a sequence of

instructionsthat tell themicrocontroller what to do.


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Why a microcontroller is needed?

Sensors Controllers Actuators


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PowerSupply

Microcontroller

Keypad

Level Switch

Temp. Sensor

Heater

Input Valve

Output ValveLCD

Alarm

Sensors M icrocontrollers Actuators


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Sensors M icrocontrollers Actuators


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Variety of microcontrollers


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Von Neumann Architecture where programs and data share asingle memory area that is accessed over a common bus. Thisscheme works well for general use computers.

Harvard Architecture Vs PIC microcontroller uses Harvard

architecture. This architecture design uses separate memory areasand buses for data and programs.

Architecture for computers:

Generally there are two types of architecture for computers


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CISC vs RISC In the early days work was done in assembly language.

Therefore CPU designers tried to make instructions that woulddo as much work as possible. This design philosophy was

named Complex Instruction Set Computer (CISC). With the advent of higher level languages, led to Reduced

Instruction Set Computer (RISC) (Simple compiler to RISC)(simpler assembly coding).

PIC microcontroller use RISC because there is a perception that

RISC is faster than CISC: Ex: A processor with MUL and other one with only ADD.

A processor with (ADD X(i),B,C) and other (ADD,Store).

Instruction Set


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PIC Peripheral Interface Controller

Microchip Technology (www.microchip.com)

Harvard Architecture

RISC

Microchip Technology (www.microchip.com)

Harvard Architecture

RISC


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PIC Microcontrollers are small computer on a chip with some specialproperties:

CPU, code memory, data memory and IO Ports all included on a singlechip.

Dedicated to one task.

Small and low cost. Embedded in many consumer devices.

Easy to program.

Better online documentation.

Low cost.

What is PIC microcontrollers?


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Which PIC microcontrollers?


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PIC SPEED

Can use crystals, clock oscillators, or even an RC circuit.

Some PICs have a built in 4MHz RC clock.

16F877 and 16F877A

Specificiations of PIC


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Specificiations of PIC

40MHz

4MHz

10MHz

20MHz

33MHz

Max. Speed


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PIC 16F877


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8 kbytes of FLASH Program Memory

368 bytes of Data Memory (RAM)

256 bytes of EEPROM Data Memory

20 MHz operating speed(200 ns instruction cycle)

Max. 25 mA current from an output pin

Low-power consumption

Wide Operating Voltage: 2.0 5.0 V

Timers Timer0: 8-bit timer/counter with 8-bit prescaler

Timer1: 16-bit timer/counter with prescaler, can be incremented during sleep via external crystal/clock

Timer2: 8-bit timer/counter with 8-bit period register,prescaler and postscaler

Capture, Compare, PWM modules Capture is 16-bit, max. resolution is 12.5 ns

Compare is 16-bit, max. resolution is 200 ns

PWM max. resolution is 10-bit

10-bit multi-channel A-to-D Converter I2C (Inter IC)Bus

USART for Serial Communication

5 I/O Ports: A, B, C, D, and E (33 input or output pins)

Specificiations PIC 16F877


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LanguagesAssemblyBASICCCode Flow

Parallel portSerial portUSB port

Programming PIC 16F877


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As a result of a successful compilationand assembling of a PIC BASIC programthe following files will be created.- BLINK.ASM - assembly file

- BLINK.LST - program listing- BLINK.HEX - executable file which iswritten into the programming memory

Pic Basic Pro


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IDE(Integrated Development

Environment)

ISE Pack (FPGA)

MikroC MpLab

Proton

PICsimulator


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Programming Languages

C-Language

Assembly BASIC


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Minimum circuitry for

PIC16F877

Power Supply

Clock generation Reset


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PIC 16F877


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PIC 16F877


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PIC 16F877


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Minimum circuitry for PIC16F877


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TRISB("TRI-State Enable" registers for port b

One register used to define if the B is set input or outputmode of each bit (1 for an input; 0 for an output).

In this example, TRISB value may be set as:

TRISB=%01110100 binary or

TRISB=$74 hex orTRISB=116 decimal


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Exercise (PicSimulator)


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PIC 16F877


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Button and Leds


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Methods of Isolation

Transistors

Optocoupler

Relay driver


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Optocoupler


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Relay driver board


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Motor Direction Control


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SPDT Relay (H-Bridge)


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Circuit Schematic


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Thank you

pic micro presentation

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