1. Fundamental of Microcontrollers
Waghmare Rahul G.

2. Introduction Purpose Objectives:
Provides an introduction to microcontrollers including usage and selection
Objectives:
Describes the functions of a microcontroller
Briefly explains the history of microcontrollers
Describes the main components of microcontroller
Talk about trends seen in the microcontroller industry
Describe the current microcontroller offerings
Describe the some of the steps in first using a microcontroller
Show usage of an Evaluation kit
Provide insight into how to choose a microcontroller for your application

3. What is Microcontroller
Single chip device
System decision based on external signals
Controls the behavior of a system
Always Contains:
Processor Core
Memory (RAM, ROM)
Input/output (I/O) Capability
Serial I/O interface
Various On-Chip Peripherals such as:
Timers
Analog to digital converters
Pulse width Modulators
Many others
Memory
I/O
Peri perals
Processor Core (CPU)

4. Where are Microcontrollers?
Everywhere
Any application that has real world inputs and outputs
Examples:
Washing Machine
ECG Machine
Networking equipments
PCOs
etc..

5. What is difference between a Microcontroller and a Microprocessor?
CPU core with memory and peripherals integrated on chip
CPU core connects to external memory and peripherals

6. What is difference between a Microcontroller and a DSP?

7. History of the Microcontrollers

8. History of the Microcontroller: Early Time

9. History of the Microcontroller: Other Early Entries
General Instruments:
The famous PIC
Spun out chip Division - Microchip
Hitachi
6300 line
Combined with Mitshibushi Electric to form Renesas
Zilog
First the Z – 80 processor, then Z – 8 MCU
PIC – Harvard architecture
Z-80 – CISC Architecture
- Improved version of the Intel 8080

10. Architecture

11. Processor Core CPU Reads and Stores data
Performs Basic Math Operations
Performs Logical functions (OR, AND etc)
Controls flow of program execution
Register Configuration changes from core to core
Addressing Modes : How CPU fetches the memory
Interrupts also changes from core to core

12. Microcontroller bit definition

13. CISC V/S RISC Complex Instruction Set Computer
CISC – Hardware is faster than software hence powerful instruction set is provided
- Uses Microcode
- Instructions are variable in length
Complex circuitry is required to decode them
RISC: - Instruction set is small
More instructions are needed to compile a task
Hardware is simple
Complex Instruction Set Computer
Reduced Instruction Set Computer

14. Harvard V/S von Neumann
Harvard: separate bus for data and instruction memory
-separate Memory allocation for each
- both data and memory can be fetched at the same time
- but memory management is more complex
Van Neumann:
Modern MCU have combination of both the architecture

15. Interrupt controller Hardware to handle interrupt signals
Important in real time system
Interrupt latency in important to consider
Hardware and software (OS) determine interrupt latency
Interrupt service routine (ISR) is the part of OS
In Real time system Interrupt handling is critical.
Interrupt controller is a piece of hardware that receives the interrupt signal, determines the priority of the interrupt, sends the interrupt request to the CPU
Interrupts can be external or Internal
The time from one interrupt event happened to when the CPU acts on interrupt is called the interrupt latency

16. System Memory: ROM ROM – Read-only Memory – for program storage
Masked ROM
Programmed during manufacture
PROM
Programmed by blowing fuse after manufacture
EPROM – Erasable ROM
Electrically programmed – Erased by UV light
OTP – One Time Programmable
EPROM that is encapsulated
EEPROM – Electrically Erasable ROM
Electrically programmed – Erased with higher voltages
FLASH
Similar to EEPROM
Write/Read/Erase in large blocks

17. System Memory: RAM RAM – Random Access Memory Types of RAM
Volatile or Non-permanent memory
Can be written to many times
Stores Temporary or changeable data
“Embedded” in MCUs
Types of RAM
SRAM
Static RAM
Fast Access times / More Silicon area
Common in MCUs
DRAM
Dynamic RAM
Slower access time / Lesser Silicon area
Less common in MCUs

18. I/O: Serial Interface Allow Communication with other devices
USB (Universal Serial Bus)
CAN (Controller Area Network)
SPI (Serial Peripheral Interface)
I2C (Inter Integrated Circuit)
UART (Universal Asynchronous Receiver/Transmitter)
LIN (Local Interconnect Network)
Ethernet
Also Wireless Interfaces
ZigBee
Bluetooth

19. On chip Peripherals Timers LCD Controllers Touch screen Controllers
Keypad Controllers
GPIO pins
A/D Converter
D/A Converter
Analog Comparator
Pulse Width Modulator

20. Trends and Current Offerings

21. Microcontroller Trends
Low Power
Dynamic Power
Static Power
Low Power Modes
Lower Supply Voltage
Higher Integration
More Feature Incorporated
Low Power
Dynamic Power
Power taken to run an application and shows the efficiency of the microcontroller
Static Power
Power Consumed during MCU standby period or lower power modes
Low Power Modes
Means to turn off the power to the device that are not in use
Lower Supply Voltage
Power consumption can also be minimized by lowering the supply voltage

22. Microcontroller Trends
32 bits
More Processing power
Flash Memory
May replace the traditional ROM
DSP Functionality
DSP or Microcontroller
Multi-core
Not just for PCs

23. Sampling of Microcontroller offerings: Licensed cores
8051
NXP, Atmel, Silicon Labs, Dallas/Maxim, ST, Rabbit and others
ARM
NXP, ST, Free-scale, Atmel, Samsung, Texas Instruments, OKI, Energy Micro and others
MIPS
Microchips
8051 – 8 bit microcontroller with Harvard Architecture
NXP – Philips
ARM – 32 bit RISC processor

24. Sampling of Microcontroller offerings: Broad range Vendors
NXP
Renesas
Microchip
Free scale
Atmel
Infineon
Texas Instruments
Samsung & ST Microelectronics
NEC
Toshiba
NXP
Formerly known as Philips
8051, ARM cores
Renesas
8 -32 bit RISC core
Microchip
PIC
DSPIC, MSIP
Free scale
Formerly known as Motorola
8-32 bit Microcontrollers
Atmel
8051 core, ARM7,9 and cortex M3, M4 and M0
AVR Architecture
Infineon
8051,Tricore,C166
Texas Instruments
16 bit MSP413
32 bit digital signal controllers
32 bit ARM devices
Samsung & ST Microelectronics
Lower cores and ARM Core
NEC
Uses only Flash Memory
Toshiba
Uses both RISC and CISC architecture

25. Sampling of Microcontroller offerings: Broad range Vendors (more..)
Analog Devices
Cyan
Maxim / Dallas
Zilog
Silicon Labs
Cypress
Energy Micro
Rabbit

26. Designing with Microcontrollers

27. Microcontroller Development Tools
Editor
Text based window for editing high-level language
Compiler
Converts source code to object code
Assembler
Converts assembly code to binary code
Linker
Joins separate object code files for download
Simulator
Run linker output on a simulation of the MCU on host PC
Debugger
Allows engineer to monitor and halt program execution

28. Microcontroller Development Tools
Integrated Development Environment (IDE)
Software package that contains all software tools integrated
In-Circuit Emulator
Replaces MCU with tool to allow viewing and control of program as seen within the chip
JTAG
Interface for test and debug
Evaluation / Development Kits
Low cost Easy-to-use Evaluation and development tool
3rd Party tools
Various tools by Non-MCU vendor that help in all aspects of development including development including kits and JTAG Debugging
JTAG – Joint Test Action Group

29. Operating System
A software platform which manages task created by user
Design team may write their own OS
Drivers handle details of using I/O and peripherals
Makes programming easier; just call on drivers for I/O
Makes program reusable; MCU hidden from designer
Drivers control peripherals; simply pass data to them
Real time Operating System (RTOS)
Designed to execute multiple tasks with definite time constraints and priorities

30. Code Development Programming code  Compiler  Memory
Highly Integrated Microcontrollers make circuit design easy but…
Must be programmed in order to perform a function
Code development is more than half the product development
A program is a sequence of instructions using the microcontroller’s unique instruction set
Families of MCUs may have a common instruction set
Typical Instruction includes:
Adding two numbers, and saving the result
Comparing two numbers and branching to different subroutines if equal or not equal
Reading the value of an external pins

31. Compiler

32. Evaluation/Development/Reference design kits
Evaluation Kit
Low cast kits
Evaluating the microcontroller
Development Kit
More comprehensive
For developing the system around the microcontroller
Reference design kits
Application specific reference designs already complete

33. Choosing a Microcontroller

34. Basics of Designing a System
Marketing analyzes market needs, Drivers & develops new product specification
Environment sensors, motors, LCD Display, Keypad, etc
Engineering determines what functions of microcontrollers are required to meet specifications
Engineering team searches for MCU & other system components that will deliver end system to specification

35. Choosing a microcontroller: General Tips
Up Front Design System
Spreadsheets
Feature Requirements
Tool Requirements
Evaluation boards
Hardware V/S Software
Complexity of MCU

36. Choosing a microcontroller: Parametric aspects
Features / On chip Peripherals
ADC
DAC
Analog Comparator
PWM
LCD Control
Timers
JTAG
I/Os
Communication Interface
USB
CAN
UART
SPI
Others…
Packages
Size
Pins

37. Choosing a microcontroller: Parametric aspects
Power
Sleep Mode
Voltage
Current
Speed
Clock frequency
Critical Instruments
Interrupt latency
Reliability
Application demand
Memory
Size
Type
Familiarity
Personal experience
Senior Engineer

38. Choosing a microcontroller: Parametric aspects
Price
Device
Volume
Software tools
IDEs
Debug
Compiler OS
Available Kits
Evaluation Kit
Development Kit
Reference design kits
Support
Documentation
White Papers
Reference design
Example code
User Guide
Errata
Application Engineers
Response time
Community
Portability
Roadmap
Large Family
Abstraction Layer

39. Thank You