The document provides an overview of microcontrollers, including a brief history of microprocessors from 1971-1993. It discusses the differences between microprocessors and microcontrollers, with microcontrollers including memory, input/output devices, timers/counters, and communication protocols on a single chip. The document outlines the various types of memory that can be included on a microcontroller, such as RAM, ROM, flash, and registers. It also describes common components of a microcontroller like analog-to-digital converters, input/output ports, and timers/counters. The document provides guidance on selecting a microcontroller based on factors like word size, memory/devices, memory architecture, instruction set, and common manufacturers.

1. Microcontroller Overview
Sally Abdelghany _ eng.sallysalem@gmail.com
Week 1
14-4-2012

2. A Brief History of Microprocessors
• In 1971 Intel 4004 at “Intel corporation“. It was the first single-chip microprocessor
was the 4-bit
• In 1972 Intel 8008 at “Intel corporation“. It was an 8-bit CPU with an external 14-
bit address bus that could address 16KB of memory.
• In (1971-1974) TMS 1000 at “Smithsonian Institution” with “Texas Instruments “
developed TMS1802NC on September 17, 1971. TMS1802NC was 4-bit, combined
read-only memory, read/write memory, processor and clock on one chip and was
targeted at embedded systems
• In 1977 Intel 8048 at “Intel corporation“. based on TMS 1000 It combined RAM
and ROM on the same chip.
• In 1993 PIC16x84 at “Microchip Technology” the introduction of EEPROM
memory allowed microcontrollers At The same year at “Atmel” introduced the first
microcontroller using Flash memory

3. Microcontroller Vs Microprocessor
• What is the microprocessor?
The microprocessor is the integration of a number of useful functions into a
single IC package.
These functions are:
• The ability to execute a stored set of instructions to carry out user defined tasks.
• The ability to be able to access external memory chips to both read and write
data from and to the memory. (Link)
• What is the microcontroller?
Is Advice that Include Microprocessor,
Memory and input/output
Devices on a single chip
(Computer on Chip)

4. Microcontroller
• Microcontroller consist of
Microprocessor +
1- Memory
2- A/D & D/A ( ‘A’ analog, ‘D’ digital)
3- I/O port
4- Timers/ Counter
5- Communication Protocols

5. • RAM (Random Access Memory)
- Volatile Type Memory
- Two Type
Memory
RAM ROM Flash Register
1- Memory
• (Flip-Flop)
• Expensive, Faster than DRAM, less power
SRAM (static)
• (Transistor, Capacitor)
• Less expensive, High power
DRAM(Dynamic)

6. • ROM (Read only Memory)
- Non Volatile Type Memory
-Types
Memory
RAM ROM Flash Register
1- Memory
• One Time Programmable (OTP)
• Cheaper than any other kind of semiconductot Memory
MROM (mask ROM)
• OR (FPROM) Filed programmable read only memory OR (OTP)
• Digital memory (Fuse or Antifuse) one time programble
PROM(Programmable Read
only memory)
• Or (UV-EPROM) can be erased by exposing into strong
Ultraviolet
• Array of floating Gate Transistors individually programmed by
Electronic Device
EPROM(Erasable
programmable Read only
Memory)
• User Modified
• Can be programmable & erased in circuit
EEPROM (Electrically
Erasable Programmable Read
only Memory)

7. • Flash memory
- non-Volatile Type Memory
-More Economical than EEPROM
- Flash is EEPROM That is erased in single stroke entire memory,
EEPROM is single erase or byte wise Rewrite memory
Memory
RAM ROM Flash Register
1- Memory

8. • Special Function Registers (SFR)
- Since their bits are physically connected to particular circuits within the
microcontroller, such as A/D converter, serial communication module etc., any
change of their state directly affects the operation of the microcontroller or some of
the circuits.
For example, writing zero or one to the SFR controlling an input/output port causes the appropriate
port pin to be configured as input or output. In other words, each bit of this register controls the
function of one single pin.
Memory
RAM ROM Flash Register
1- Memory

9. • ADC
- Is the Device that converts a continuous quantity to a Discrete time digital
representation
*Resolution (Sampling process)
The resolution of convert indicates the number of Discrete values it can produce
over the range of analog values
> the values are usually stored electronically in binary form so the resolution
is usually expressed in bit
• DAC
– Convert the Digital signal to Analog
2- ADC & DAC

10. • Input/ Output port
There are two main port types, parallel and serial,
- Parallel I/O requires a data line for each bit
- Serial I/O uses a single line and transfers bits in sequence.
and two port modes, synchronous and asynchronous.
- Synchronous I/O is synchronized to a clock
- Asynchronous I/O is not.
Microcontrollers most often have parallel I/O capability built in and serial I/O as
peripheral feature.
3- Input / output Port

11. • Timer / Counter
- A timer is a counter that is incremented at a fixed rate when the system clock
pulses.
- There are several different types of timers available. A timer/counter
can perform several different tasks.
- The CPU uses the timer
1- to keep track of time accurately.
2- timer can generate a stream of pulses or a single pulse at different
frequencies. It can be used to start and stop tasks at desired times.
A COP (computer operating properly) or watchdog timer checks for runaway
code execution. The hardware implementation of watchdog timers varies
considerably between different processors. In general watchdog timers must be
turned on once within the first few cycles after reset and then reset periodically
with software. (page 17, BC FirstSteps)
4- Timers/ Counter

12. • UART
• SCI
• SPI
• I2C
• CAN
• LAN
5- Communication protocol

13. How choose Microcontroller?
Bits
The lengths of microprocessor’s data words.
- 4-Bit
- The 4 bit microprocessor was the first one developed.
- Microprocessors of this word length are still popular in some types of
work
EX
- The Intel 4004, the world's first commercially available single-chip
microprocessor, was a 4-bit CPU.
- The F-14 Tomcat's Central Air Data Computer (or F14 CADC) was
created a year before the 4004

14. How choose Microcontroller?
Bits
The lengths of microprocessor’s data words.
- 8-Bit
- The 8 bit word length is twice 4 bits.
- The 8 bit word length can hold all the data needed for one character in
American Standard Code for Information Interchange (ASC II)
EX
- The Intel 8080 was The first widely adopted 8-bit microprocessor
- The Zilog Z80 (compatible with the 8080) and the Motorola

15. How choose Microcontroller?
Bits
The lengths of microprocessor’s data words.
- 16-bit
EX: PDP-11, Intel 8086, Intel 80286 and the WDC 65C816. The Intel 8088
- 32-bit
EX: Intel 80960 family and Motorola M683xx and Intel/Atmel 251 family.
-32-bit instruction set architectures include the IBM System/360 and its 32-bit
successors, the DEC VAX, the ARM architecture, the MIPS architecture,
and the Intel IA-32.

16. How choose Microcontroller?
Memory/Devices
Embedded
When an embedded system has an microcontroller unit that has all the functional
blocks available on a chip is called an embedded microcontroller.
EX, 8051 having Program & Data Memory, I/O Ports, Serial Communication, Counters and Timers and
Interrupt Control logic
External
In external memory microcontroller, all or part of the memory units are externally
interfaced using an interfacing circuit called the glue circuit.
EX, 8031 has no program memory on the chip is an external memory microcontroller.

17. How choose Microcontroller?
Memory architecture
Von Neumann Architecture:
In this architecture, program and data are stored together and are accessed
through the same bus.
- Unfortunately, this implies that program and data accesses may conflict (resulting in the
famous von Neumann bottleneck), leading to unwelcome delays.
Harvard Architecture:
This architecture demands that program and data are in separate memories which are
accessed via separate buses.
- In consequence, code accesses do not conflict with data accesses which improves system
performance.
- As a slight drawback, this architecture requires more hardware, since it needs two busses
and either two memory chips or a dual-ported memory
(a memory chip which allows two independent accesses at the same time).

18. How choose Microcontroller?
Instruction Set
RISC:
 Reduced Instruction Set Computer
 Usually each instruction takes only 1 cycle to execute
 Emphasis on software
 Complexity on software side
 Register-to-Register : load and store are separate instructions
SISC:
 Specific Instruction Set Computer
 Single Instruction may take more than 1 cycle to execute
 Complexity found in hardware
 Memory-to-memory : load and store functionality found in a single instruction

19. How choose Microcontroller?
Instruction Set
RISC:
 all instructions of a uniform size
 instructions are easier to decode because of how they are set up-ex: opcode will
always be in the same place
 capable of using pipelining by design
SISC:
 instructions not always the same size
 instructions are difficult to decode because instructions are not uniform
 to make use of pipelining, instructions need to be broken down to smaller
components at processor level

20. CISC vs. RISC
RISC:
 The Total clock cycles for the RISC version is:
(3 movs × 1 cycle) + (5 adds × 1 cycle) + (5 loops × 1 cycle) = 13
cycles
SISC:
 The total clock cycles for the CISC version might be:
(2 movs × 1 cycle) + (1 mul × 30 cycles) = 32 cycles

21. List of common microcontrollers
This is a list of common microcontrollers
listed by brand.
1 AMCC
2 Altera
3 Analog Devices
4 Atmel
5 Charmed Labs
6 Cypress Semiconductor
7 Dallas Semiconductor
8 ELAN Microelectronics Corp.
9 Energy Micro AS
10 EPSON Semiconductor
11 Freescale Semiconductor
12 Fujitsu
13 Holtek
14 Infineon
15 Intel
16 Lattice Semiconductor
17 Microchip Technology
18 National Semiconductor
19 NEC
20 Panasonic
21 Parallax
22 NXP Semiconductors
23 Rabbit Semiconductor
24 Renesas Electronics
25 Rockwell
26 Silicon Laboratories
27 Silicon Motion
28 Sony
29 STMicroelectronics
30 Texas Instruments
31 Toshiba
32 Ubicom
33 Xemics
34 Xilinx
35 XMOS
36 ZiLOG
37 Sortable table

22. Standard interface that can be controlled directly by microcontroller
PIC
AVR
ARM
Arduino
DSP
MSP430
TTL Logic