1. Parul Polytechnic Institute
Subject Code :
Name Of Subject : Microprocessor and assembly language programming
Name of Unit : Introduction to microprocessor
Topic : MICROPROCESSOR AND INTERFACING
Name of Faculty : H.M.Avaiya & N.D.Dhameliya
Name of Students: (i) BARIYA KARANKUMAR J(072)
(ii) MODI JHINAL T(074) 1

2. MICROPROCESSOR AND INTERFACING
AUTHORS :RAMESH.S.GAONKAR
BADRI RAM
DOUGLAS.V.HALL
LIU AND GIBSON

3. Syllabus of Microprocessor
Introduction to microprocessor
Architecture and block diagram of microprocessor
8085 microprocesso
8237 DMA Controller
8255 Programmable peripheral interface device
8254 programmable interval timer
8259 programmable inttrupt controller
8086 microprocessor

4. What is Microprocessor?
A silicon chip that contains a CPU. In the world of personal computers, the terms microprocessor and CPU are used interchangeably. At the heart of all personal computers and most workstations sits a microprocessor. Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles

5. Microprocessor def.. Con..
Microprocessor is a programmable device
It can be instructed to perform given tasks with in its capability.
The programmer selects instruction from the list and determines the sequence of execution for a given task.
It takes input from the input device and process the input as it behaves like a CPU and gives the output.

6. Microprocessor def.. Con..
Microprocessor is a clock driven semiconductor device consisting of electronic logic circuits manufactured by using a LSI or VLSI technique.
Microprocessor can be divided into three segments
1)ALU
2)Register array
3)Control unit

7. Block diagram of microprocessorAs
CPU
OUTPUT
INPUT
MEMORY

8. Characterstics which differentiate microprocessors
Instruction set: The set of instructions that the microprocessor can execute.
bandwidth : The number of bits processed in a single instruction.
clock speed : Given in megahertz (MHz), the clock speed determines how many instructions per second the processor can execute.

9. Structure of microprocessor
Chip containing no. of elements for the processing purposes.

10. History of microprocessor
Intel's 4004 is considered the first microprocesor .
The 4004 was later followed in 1972 by the 8008, the world's first 8-bit microprocessor.

11. History of microprocessor……
then is the 8080 microprocessor evolved in 1974.
Then comes 8085 that is the 8 bit microprocessor

12. Continued…
Often the processor is required to manage various different tasks that have to be scheduled somehow and must also deal with outside interrupt sources such as an alarm when something goes wrong.
Real-time systems are those in which timeliness is as important as the correctness of the outputs, although this does NOT mean that they have to be ?fast systems?.
A real-time system does not have to process data in microseconds to be considered real-time - it must simply have response times that are constrained and thus predictable.

13. Real life applications of microprocessor
Microprocessors are used to handle a set of tasks that control one or more external events or systems.
Microprocessors are typically used in either reactive or embedded systems.
Reactive systems are those that have an ongoing interaction with their environment - for example, a fire-control system that constantly reacts to buttons pressed by a pilot.
Embedded systems are those used to control specialized hardware in which the computer system is installed - for example, the microprocessor system used to control the fuel/air mixture in the carburetor of many automobiles.
 In embedded systems the software system is completely encapsulated by the hardware that it controls.

14. Some questions What is SSI,MSI and LSI?
What is difference between microprocessor, microcontroller and microcomputer?
What is a bit, byte, nibble and a word?
What is difference between compiler and interpreter?
What is instruction and mnemonic?

15. 8085 programming model Program counter Stack pointer
General purpose registers
Accumulator
Flag registers
Data and address buses

16. 8085 instruction set Data transfer operations Arithmetic operations
Logical operations
Branch operations
Machine control operations

17. Data transfer operations
MOV Rd,Rs
MVI R,8 bit
HLT
IN bit port address accept the data from the input port specified in the second byte and loads into the accumulator.
NOP
OUT 8 bit port address copies the contents of the accumulator to the output port specified in the second byte,2 byte instruction

18. Data transfer operations
This group of instructions copies data from a location called a source to another a location called destination without modifying the contents of the source.
Data transfer can be between 1)registers
Specified data byte to a register or memory location
Between a memory location and a register

19. Addressing mode Immediate addressing mvi Register addressing mov
Direct addressing in/out ports
Indirect addressing

20. Logical operations
ANA R
ANI 8 bit
ORA R
ORI bit
XRA R
XRI 8 bit
CMA

21. Arthimetic operations
ADD R
ADI 8 bit
SUB R
SUI 8 bit
INR R
DCR R

22. Branch operations
JMP 16 bit 2nd(low) and 3rd(high) byte specifies 16 bit
Memory address JC
JNC JZ
JNZ JP JM

23. Microprocessor architecture
The process of data manipulation and communication is determined by the logic design of the microprocessor called the arcitecture.

24. Microprocessor architecture
Microprocessor initiated operations
Internal operations
Externally initiated operations
To perform these functions microprocessor requires a group of logic circuits and set of signals called control signals.

25. Microprocessor initiated operations
Memory read
Memory write
I/O read
I/O write

26. Internal operations Store 8-bit data
Perform arthimetic and logical operations
Test for conditions
Sequence the excuetion of operations
Store data temporarily during excuetion

27. 8085 pin diagram
Is 8 bit microprocessor, capable of addressing 64k of memory
Has 40 pins ,operate with 3mhz single phase clock
Require +5v of single power supply

28. 8085 pin diagram

29. 8085 pin diagram
Is 8 bit microprocessor, capable of addressing 64k of memory
Has 40 pins ,operate with 3mhz single phase clock
Require +5v of single power supply

30. Pin diagram conti…. All the signals are classified into 6 groups
Address bus
Data bus
Control and status signals
Power supply and frequency signals
Externally initiated signals
Serial input output ports

31. Block diagram of 8085 microprocessor
It includes
Arithmetic and logic unit
Timing and control unit
Instruction register and decoder
Register array
Interrupt control
Serial input output control

32. 8085 interrupt What is interrupt? Vectored interrupt
Non vectored interrupt
Enable and disable interrupt instructions
Pending interrupts

33. 8085 interrupt
Interrupt is a process where an external device can get the attention of the microprocessor.
The process starts from the I/O device
The process is asynchronous.
Classification of Interrupts
Interrupts can be classified into two types:
Maskable Interrupts (Can be delayed or Rejected)
Non-Maskable Interrupts (Can not be delayed or Rejected)
Interrupts can also be classified into:
Vectored (the address of the service routine is hard-wired)
Non-vectored (the address of the service routine needs to be supplied externally by the device)

34. Interrupts
An interrupt is considered to be an emergency signal that may be serviced.
The Microprocessor may respond to it as soon as possible.
What happens when MP is interrupted ?
When the Microprocessor receives an interrupt signal, it suspends the currently executing program and jumps to an Interrupt Service Routine (ISR) to respond to the incoming interrupt.
Each interrupt will most probably have its own ISR.

35. Interrupts
When a device interrupts, it actually wants the MP to give a service which is equivalent to asking the MP to call a subroutine. This subroutine is called ISR (Interrupt Service Routine)
The ‘EI’ instruction is a one byte instruction and is used to Enable the non-maskable interrupts.
The ‘DI’ instruction is a one byte instruction and is used to Disable the non-maskable interrupts.
The 8085 has a single Non-Maskable interrupt.
The non-maskable interrupt is not affected by the value of the Interrupt Enable flip flop.

36. 8085 intrrupts
TRAP
RST7.5
RST6.5
RST 5.5
INTR
INTA

38. Interrupt Vectors and the Vector Table
An interrupt vector is a pointer to where the ISR is stored in memory.
All interrupts (vectored or otherwise) are mapped onto a memory area called the Interrupt Vector Table (IVT).
The IVT is usually located in memory page 00 (0000H - 00FFH).
The purpose of the IVT is to hold the vectors that redirect the microprocessor to the right place when an interrupt arrives.

39. GENERAL PURPOSE PROGRAMMABLE PERIPHERAL DEVICES

40. 8255A Programmable peripheral interface
8254 programmable interval timer
8259 Programmable interval timer
8237 DMA Controller

41. 8255 Programmable peripheral interface
It can be programmed to transfer data under various conditions.
It has 24 I/O pins.
The function of 8255A classified acc to two modes.
A) BSR mode
I/O mode

42. 8255 Programmable peripheral interface
Block diagram of 8255A
Control word
BSR mode
Mode 0
Mode 1
Mode 2

43. For port C Mode0 Mode 1 Mode2
Control Word
D7 D6 D5 D4 D3 D2 D1 D0
0/1
BSR Mode I/O Mode
For port C Mode0 Mode 1 Mode2
No effect on mode Simple I/O Handshake I/O
for ports for ports A and or B
A,B,C
Port C bits

44. 8254 Programmable interval timer

45. 8237 DMA Controller
DMA is an input output technique used for high speed data transfer
Data transfer between system memory and floppy disk
It introduces two new signals that are
HOLD
HLDA

46. DMA Controller cont…. DMA Controller consists of
DMA channels and interfacing
DMA Signals
System interface
Programming the 8237
DMA Execution consists of
Master and slave mode

47. 8086 microprocessor It is 16 bit microprocessor.
Contains transistors and is fabricated using HMOS technology.
Has addressing capacity of I megabyte.
Has 20 address pins.
+5v supply voltage

48. 8086 Arcitecture Internal registers Control logic Instruction queue
ALU
PSW
Pointers
Segment registers

49. 8086 pin diagram

50. 8086 effective address computations
To provide flexible base addressing and indexing a data address may be formed by addressing together a combination of the BX or BP register contents SI or DI contents and a displacement.The result of such and address computation is called effective address.

51. 8086 memory segmentation
Address within segments
Overlapping segments

52. Program relocation using CS register
If a programmer wants to relocate the program by any means ,he can relocate the program using cs register.