Embedded System Spring, 2011 Lecture 3: The PIC Microcontrollers Eng. Wazen M. Shbair

IUG- Embedded System2 Today’s Lecture  Comparison between Microprocessors and Microcontrollers.  Advantages of Microcontroller.  Criteria for considering Microcontroller.  Overview of the PIC18 Family

IUG- Embedded System3 Microprocessor vs. Microcontroller  Microprocessor is general-purpose microprocessors such as Intel’s x86 family.  Microprocessor dose not contain RAM, ROM or I/O Ports on the chip it self.  Microcontroller has CPU and fixed amount of RAM, ROM, I/O Ports and Timer all on a single chip.

IUG- Embedded System4 Microprocessor vs. Microcontroller

IUG- Embedded System5 Microprocessor vs. Microcontroller  Microprocessor and Microcontroller are widely used in embedded system products.  Typically, in an embedded system the microcontroller’s ROM is burned with a purpose for specific functions needed for the system. (e.x. Printer)

IUG- Embedded System6 Choosing a µController  The major 8-bit Freescale Semiconductor’s (formerly Motorola) 68HC08/68HC11 Intel’s 8051 Atmel’s AVR Zilog’s Z8 PIC from Microchip Technology

IUG- Embedded System7 Criteria for Choosing µController 1.Meeting the computing needs of the task at hand efficiency and cost effectively 2.Availability of SW and HW development tools Compilers Assemblers Debuggers Emulators 3.Wide availability and reliable source.

IUG- Embedded System8 Criteria for Choosing µController  Meeting the computing needs of the task at hand efficiency and cost effectively Determine its type, 8-bit,16-bit or 32-bit Speed Packaging (40-Pin or QFP) Power consumption The amount of RAM and ROM The number of I/O pins and the timer Cost per unit Ease of upgrade. 3-8

IUG- Embedded System9 µC Data width  8-bit Microcontrollers PIC10, PIC12, PIC14 PIC16, PIC17, PIC18  16-bit Microcontrollers PIC24F, PIC24H  32-bit Microcontrollers PIC32  16-bit Digital Signal Controllers dsPIC30, dsPIC33F

IUG- Embedded System10 Overview of the PIC18 Family  An 8-bit µController called PIC is introduces in 1989 by Microchip Technology Corporation  It includes Small Data RAM Few bytes of ROM One timer I/O ports 3-10

IUG- Embedded System11 PIC 18 Feathers  RISC Architecture  On-chip program, Code, ROM  Data EEPROM  Timers  ADC  USART  I/O Ports

RISC Architecture  Reduced Instruction Set Computer (RISC)  Small, highly optimized set of instructions  Uses a load-store architecture  Short execution time  Pipelining  Many registers

IUG- Embedded System13 Figure 1-2. Simplified View of a PIC Microcontroller 3-13

IUG- Embedded System14 PIC18 Features  RISC Architecture  On chip Code ROM and Data RAM, Data EEPROM  Timers  ADC  USART  I/O ports

IUG- Embedded System15 Microcontroller 3-15

IUG- Embedded System16 PIC µC program ROM  PIC exists in terms of different speed and the amount of on-chip RAM/ROM  Compatibility is restricted as far as the instructions are concerns. 3-16

IUG- Embedded System17 PIC µC Program ROM  Its used to store Program or code  PIC 18 can support up to 2MB  Generally, they come with 4KB – 128KB  Available in flash, OTP, UV-EPROM, and masked.

IUG- Embedded System18 UV-EPROM 3-18

IUG- Embedded System19 PIC18Fxxxx with flash  Its on chip ROM is flash  It memory can be erased in second compared to 20 minute needed for UV-EPROM  Used for product development

IUG- Embedded System20 PIC18Cxxxx and Masked PIC  One Time Programmable (OTP) C indicates the OTP RPM Used for mass production Cheaper  Masked program will be burned into the PIC chip during the fabrication process

IUG- Embedded System21 PIC C data RAM and EEPROM  Max Bytes (4 kB) of data RAM space.  Data RAM space has two components Varied GPR, General Purpose RAM  For read/write and data manipulation  Divided into banks of 256 B Fixed SFR, Special Function Registers  Some of PICs have a small amount of EEPROM Used for critical data storing

IUG- Embedded System22

IUG- Embedded System23 PIC µC peripherals  CAN- (Controller Area Network),  LIN- (Local Interconnect Network),  USB- (Universal Serial Bus),  I²C- (Inter-Integrated Circuit),  SPI- (Serial Peripheral Interface),  Serial or Ethernet Interface  ADC - Analog Digital Converter  USART- Universal Synchronous Asynchronous Receiver Transmitter 3-23

IUG- Embedded System24 References  Jie Hu, ECE692 Embedded Computing Systems, Fall  PIC Microcontroller And Embedded Systems: using Assembly and C for PIC 18, M. Mazidi, R. McKinlay and D. Causey, Prentice Fall,  Eng. Husam Alzaq, Embedded System Course, IUG, 2010