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EECE416: Microcomputer Fundamentals and Design

PIC - Introduction

PIC16F877

Dr. Charles J. Kim

Howard University

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Peripheral Interface Controller

PIC: Peripheral Interface ControllerMicrochip Technology (www.microchip.com)Harvard Architecture

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PIC- continued

Origin: Harvard Architecture for DAPRA ProjectBeaten by Princeton (Single memory)Picked by Signetics 8x300PIC for General InstrumentsCompensation for poor I/OGI spun off into Arizona Microchip Technology (1985)- Microchip Technology

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PIC -continuedA Large Register Set: 368 Bytes + WRISC Architecture--pipelining35 fixed length (14-bit) single-cycle instructions

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PIC-continued8-bit machineOperating Speed: Up to 20 MHz8K 14-bit Words FLASH Memory (for Program)368 Bytes RAM (for Data)256 Bytes EEPROM (for Data)Power Saving Mode

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PIC -continued

Low-power consumption:< 2 mA typical @ 5V, 4 MHz20 mA typical @ 3V, 32 kHz< 1 mA typical standby current

Wide Operating Voltage: 2.0 – 5.0 VTimers

Timer0: 8-bit timer/counter with 8-bit prescalerTimer1: 16-bit timer/counter with prescaler, can be incremented during sleep via external crystal/clockTimer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler

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Capture, Compare, PWM modulesCapture is 16-bit, max. resolution is 12.5 nsCompare is 16-bit, max. resolution is 200 nsPWM max. resolution is 10-bit

10-bit multi-channel A-to-D Converter I2C (Inter IC)BusUSART for Serial Communication5 I/O Ports: A, B, C, D, and E

PIC -continued

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16F87x Family

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PIN and PACKAGE

DIP

QFP

PLCC

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PIN

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F877 Architecture

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BLOCK Diagram

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8AD

TXRX

W

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ALU and W register

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PROGRAM MEMORY

13-bit PCAddressable up to 8Kx14-bitFLASH Memory Reset Vector: $0000Interrupt: $0004

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DATA memory (“Register File”)

Partitioned into 4 Banks (or Pages): 0-3Each Bank: 128 BytesUpper Locations: GPR (General Purpose) Reg.--RAMLower Location: SFR (Special Function) Reg.BANK SELECTION:

Status RegisterRP1: Status<6>RP0: Status<5>

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Register File Map

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Special Function Registers (bank 0)

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Special Function Registers (bank 1)

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Special Function Registers(bank 2 & 3)

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Input/Output Ports

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Interrupts

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16F877 Hex Code Download

PIC Programmer

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Boot Loader Option

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PIC16F877 Bootloader

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Minimum Hardware for Boot Loaded Platform

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Commercially Available PIC16F877 Board

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PIC-40B-USB Schematic

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PIC-40B-USB Schematic (PIC area only)

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Other PIC Board (Not fully evaluated yet)DLP-245PB-G-USBNot evaluatedProblem in Bootloader downloading

Problem in USB driver with Windows