INTRODUCTION TO MICROPROCESSOR : INTRODUCTION TO MICROPROCESSOR Presented by
SUDHIR REDDY S.VR
MTECH[CAD/CAM] Microprocessor Generations : Microprocessor Generations First generation: 1971-78
Behind the power curve (16-bit, <50k transistors)
Second Generation: 1979-85
Becoming “real” computers (32-bit , >50k transistors)
Third Generation: 1985-89
Challenging the “establishment” (Reduced Instruction Set Computer/RISC, >100k transistors)
Fourth Generation: 1990-
Architectural and performance leadership (64-bit, > 1M transistors, Intel/AMD translate into RISC internally) Introduction : Introduction Focus on microprocessors as general purpose, flexible and reconfigurable controllers and the ways sensors and actuator relate to these.
Microprocessors are often called microcontrollers
What is a microprocessor? What is the different between a microprocessor and a computer or a microcomputer and how a distinguishing set of features is arrived at are all difficult and subjective issues. What is a microprocessor to one is a full fledged computer to another The microprocessor : The microprocessor microprocessor is a stand alone, self contained single chip microcomputer.
It must have as a minimum:
a central processing unit (CPU)
nonvolatile and program memory
input and output capabilities.
A structure that has these can be programmed in some convenient programming language
can interact with the outside world through the input/output ports. MICROPROCESSOR : MICROPROCESSOR MICROPROCESSOR : MICROPROCESSOR The microprocessor : The microprocessor Other important requirements:
must be relatively simple
necessarily limited in most of its features – memory, processing power and speed, addressing range and, of course in number of I/O devices it can interact with.
The designer must have access to all features of the microprocessor – bus, memory, registers, all I/O ports,
In short, Microprocessors are components with flexible features that the engineer can configure and program to perform task or a series of tasks. The microprocessor : The microprocessor Two limits on the tasks microprocessors can perform:
The limitations of the microprocessor itself
The imagination (or capabilities) of the designer. The 8 bit microprocessor : The 8 bit microprocessor We will narrow down to 8 bit microprocessors
these are the most common in sensor/actuator systems
they are simple and representative of all microprocessor
16 and 32 bit microprocessors exist
There are a number of architectures being used.
We will emphasize the Harvard architecture because of its simplicity, flexibility and popularity. Addressing : Addressing 8 bit microprocessors have word length of 8 bits.
Integer data from 0 to 255 may be represented directly.
To address memory, usually a longer word is needed.
Most microprocessor have a 12 bit (4k) 14 (16k) or 16 bit (64k) memory address but longer address words are also used. Speed : Speed Most microprocessor operate at clock speeds between 1 and 40 MHz.
Since often the clock is internally divided, the instruction cycle is slower than that
Typical values are up to about 10 MHz cycle clock or 0.1 s per instruction Input and output : Input and output Input and output is defined by the availability of pins on the package.
Usually limited to less than about 100 pins (6, 8, 14, 18, 20, 28, 32, 40, 44, 64 and 100 pins are common).
Two pins are used to power to the device
For example, an 18 pin device can have no more than 14 I/O pins.
Of these, some may be used for other purposes such as oscillators or communication Clock and timers : Clock and timers Microprocessors have internal timers
under the control of the user
used for various functions requiring counting/timing
At least one counter is available
larger microprocessors can have 4 or more timers
some are 8 bit timers and some 16 bit timers.
a watchdog timer is available for the purpose of resetting the processor should it be “stuck” in an inoperative mode. Other functionalities : Other functionalities Many microprocessors provide multiple interfaces, all under the user’s control.
Other functions such as analog amplifiers and even transceivers are sometimes incorporated within the chip.
The I/O used for these functions are either digital I/O (for communication for example) or analog Programs and programmability : Programs and programmability microprocessor is only useful if it can be programmed.
Programming languages and compilers have been designed specifically for microprocessors.
The basic method of programming microprocessors is through the Assembly programming language
Can be, and very often is done through use of higher level languages with C leading.