Untitled Quiz

• This lecture will cover the AVR Microcontroller and embedded system designing

Grading Breakdown

• Mid-term exam: 30%
• Final exam: 40%
• Laboratory work: 30%

Syllabus of Microcontroller Course

• Introduction to Microprocessors and Microcontrollers, differentiating between them
• AVR Microcontroller: History and Features
• AVR Microcontroller Architecture
• C Review is on the syllabus
• AVR Programming and Applications with Mega 32/16
• I/O Ports.
• LCD
• Timers/Counters
• Keypads
• Analog to Digital Converter “A/D”
• Motor Control with PWM

Introduction to Microcontrollers

• A Microcontroller is a single chip, self contained computer
• Microprocessors and Microcontrollers differ mainly in operation and peripherals

Microprocessor vs Microcontroller

• Microprocessors are for only processing data and are faster, serving as general purpose processors, but are more expensive
• In microprocessors, the CPU is stand-alone and RAM, ROM, I/O, and timer are separate
• The designer can control the amount of ROM, RAM, and I/O ports
• Microprocessors are cheaper than microcontrollers with the same features
• Microcontrollers are slower, operate stand-alone, and are cheaper including CPU, RAM, ROM, I/O, and timer all on a single chip but with a fixed amount
• Microcontrollers are used in applications where cost, power, and space are critical

History of Microcontrollers

• 1971: Texas Instruments created TMS 1000, a 4-bit microcontroller with built-in ROM and RAM
• 1976: Intel released the 8048, one of their first microcontrollers
• 1980: Intel's 8051 became one of the most popular microcontroller families
• 1996: Atmel AVR was among the first to use on-chip flash memory for program storage

AVR Family Types

• TINY AVR Family: 8-32 pin with 16 family members
• MEGA AVR Family: 32-100 pin with 23 family members
• XMEGA AVR Family: 32-100 pin

Classic AVR Microcontrollers

• AT90S series: Classic AVR members with fewer features and less word usage.
• ATtiny series: Small microcontrollers (8-32 base) with enhanced capabilities for systems needing minimal port usage, operating at 8 bits.
• ATmega Series: Offers more features, is self-programmable, and is programmable using additional circuits operating at 8 bits with 4-256 KB program memory.
• ATxmega series: Largest and most advanced, featuring 16-384 KB program memory and operates at 16 bits.

Microcontroller Components

• CPU, Memories, Input/output ports, Timer/counter, Parallel ports, Interrupt sources, PWM function, (A/D , D/A) converters

CPU - Central Processing Unit

• It is the brain of a microcontroller, responsible for fetching instructions, decoding, and executing them
• The CPU connects every microcontroller part into a single system
• Decoding is done by the CPU of instruction fetched from program memory
• CPU carries out the Fetch, Decode, and Execute cycle

CPU Components

• Register
• ALU (Arithmetic Logic Unit): Performs arithmetic and bitwise operations
• CU (Control Unit): Decodes instructions and controls internal components.

Register Details

• Registers are quickly accessible locations which may hold an instruction, a storage address, or any kind of data
• Accumulator register: used for storing intermediate arithmetic and logic results
• Flag register: status register; bit values indicate conditions after instruction execution
  • ZF flag (zero flag): ZF=1 if instruction results in zero
  • Sign flag : SF=1 if sign of instruction is negative
• Program counter or instruction pointer register: Indicates CPU's program sequence, containing the address of the next instruction

Memory Types

• Several types divided into Volatile RAM (random access memory) and Non-Volatile ROM (read-only memory) and Flash memory

RAM Details

• RAM (Random Access Memory): static and dynamic
  • SRAM (Static RAM): expensive, high-performance, constructed of Flip-Flops
  • DRAM (Dynamic RAM): cheap, constructed from Capacitors (periodically refreshed) and divided into:
• SDRAM (Synchronous DRAM)
  • SDR-SDRAM (Single Data Rate)
  • DDR-SDRAM (Double Data Rate): DDR-SDRAM is now commonly ised due to having better and faster performance

ROM

• ROM (Read Only Memory Types)
  • ROM (ROM)
  • PROM (Programmable ROM)
  • EPROM (Erasable PROM by UV light)
  • EEPROM (Electrically Erasable PROM).

Flash Memory

• Flash Memory is a non-volatile memory that is electrically erased and reprogrammed
• Flash Memory is used for memory cards and USB flash drives
• Flash Memory is a specific is an EEPROM (Electrically Erasable Programmable Read-Only Memory) that is erased and programmed in large blocks (faster than EEPROM)

I/O Ports

• Input/Output ports
• Parallel input/output ports used to drive/interface devices like LCD's, LED's, printers, memories, etc to a microcontroller