Exploring Features of MDB-1000(PIC18 & 32)

8/8/2019 Exploring Features of MDB-1000(PIC18 & 32)

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Exploring Features of

MDB-1000(PIC18 & 32)Guided By:- Prof. Sachin H. Gajjar

Prepared By:-

Shah Suyog (07BEC096)

Vyas Nisarg (07BEC115)


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Introduction About MDB-1000

Harvard and Von Neuman Architecture

PIC Architecture:- BackGround PIC Microcontroller Overview

Difference Between Different 8-bit PIC MCUs

Baseline, Mid-Range, Enhanced Mid-Ranged and PIC18 Architecture

Block Diagram

PIC18F4550 Explanation which is used in the MDB-1000 About Our Project

The Things that we have done till today


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MDB-1000(MultiPurpose

Developement Board)

USART port for serial communication

ETHERNET cable

LCD touch screen

Both 16 bit and 32 bit controllers

Industrial specific and thus has a lot of scope forexploration


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Software Used MPLAB IDE v8.2a

MPLAB C18 C Compiler

Taken from the microchip website only

Easy to work on , shows the outputs and gives

proper errors when erred

Provides the facility of checking all the peripherals

of the kit


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Harvard Von-Neuman Architecture Von Neumann Architecture:

Fetches instructions and data

from a single memory space

Limits operating bandwidth

Harvard Architecture:

Uses two separate memory

spaces for program

instructions and data

Improved operating

bandwidth

Allows for different bus

widths


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PIC Architecture:- BackGroundMicroprocessor:

Requires external support hardware

E.g., External RAM, ROM, Peripherals.

Microcontroller:

Very little external support hardware.

Most RAM, ROM and peripherals on chip.

Computer on a chip, or System on chip (SOC)

E.g., PIC = Peripheral Interface Controller


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PIC Architecture:- BackGroundWere used to the Von-Neuman Architecture

Used in: 80X86 (PCs), 8051, 68HC11, etc.)

Only one bus between CPU and memory

RAM and program memory share the same bus and the same memory,

and so must have the same bit width

Bottleneck: Getting instructions interferes with accessing RAM

CPU8

Memory

(Program &Data)


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PIC Architecture:- BackGroundPICs use the Harvard Architecture

Used mostly in RISC CPUs (well get there)

Separate program bus and data bus: can be different widths!

For example, PICs use: Data memory (RAM): a small number of 8bit registers

Program memory (ROM): 12bit, 14bit or 16bit wide

(in EPROM, FLASH, or ROM)

CPU121416

Memory

(Data) 8

Memory

(Program)


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PIC Architecture:- BackGround

Traditionally, CPUs are CISC

Complex Instruction Set Computer (CISC)

Used in: 80X86, 8051, 68HC11, etc.

Many instructions (usually > 100)

Many, many addressing modes

Usually takes more than 1 internal clock cycle (Tcyc) to execute


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PIC Architecture:- BackGround

PICs and most Harvard chips are RISC

Reduced Instruction Set Computer (RISC)

Used in: SPARC, ALPHA, Atmel AVR, etc.

Few instructions (usually < 50)

Only a few addressing modes

Executes 1 instruction in 1 internal clock cycle (Tcyc)


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Microcontroller Architecture

PIC18F Family


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PIC18F Microcontroller Families PIC microcontrollers are designed using the

Harvard Architecture which includes:

Microprocessor unit (MPU)

Program memory for instructions

Data memory for data

I/O ports Support devices such as timers


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PIC18F MCU and Memory

2 MB

221

4 KB

212

16 bit

8 bit


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Microprocessor Unit Includes Arithmetic

Logic Unit (ALU),

Registers, and ControlUnit

Arithmetic Logic Unit

(ALU)

WREG working register

Status register that stores

flags

Instruction decoder

when the instruction is

fetched it goes into the ID


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PIC18F - Address Buses Address bus

21-bit address bus for

program memoryaddressing capacity: 2 MB

of memory

12-bit address bus for data

memory addressing

capacity: 4 KB of memory


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Data Bus and Control Signals Data bus

16-bit instruction/data

bus for program memory

8-bit data bus for data

memory

Control signals

Read and Write


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PIC18F Special Features Sleep mode

Power-down mode

Watchdog timer (WDT) Able to reset the processor if the program is caught in

unknown state (e.g., infinite loop)

Code protection

EEPROM can be protected through SFR

In-circuit serial programming

In-circuit debugger


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Targets

Thoroughly exploring each and every feature of the

PIC microcontroller while working on the PIC kit Make an application encompassing the explored

features of the microcontroller

Proposed application: E-menu

Uses- in hotels and restaurants


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Targets achieved so far Initially faced problems due to desultory

documentation provided by the company

Diversion to ATMEGA 128L But now back on track

Code Programming done in C language

Started with few simple codes to get acquainted

Made a GPIO board and have done several

programmes on it


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Continued

Program 1 To toggle the lights on GPIO board

with some delay Program 2- To give the input from outside and

switch on a particular port

Program 3- To give the input from outside and

switch on the lights continously but alternately

Next to work on USART and TIMERS


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Thank You

Documents

Exploring Features of MDB-1000(PIC18 & 32)