8085 Microprocessor

1. PRESENTATIONPRESENTATION
ONON
INTRODUCTION TOINTRODUCTION TO
MICROPROCESSORMICROPROCESSOR
PRESENTED BY:PRESENTED BY:
Adarsh KumarAdarsh Kumar

2. WHAT IS
MICROPOCESSOR?

3. MICROPROCESSORMICROPROCESSOR
Microprocessor is an electronic circuit that functions asMicroprocessor is an electronic circuit that functions as
the central processing unit (CPU) of a computer,the central processing unit (CPU) of a computer,
providing computational control.providing computational control.
The Microprocessor, (or CPU), is the brain of theThe Microprocessor, (or CPU), is the brain of the
computercomputer..
A microprocessor isA microprocessor is “a component that implements“a component that implements
memorymemory.”.”
Microprocessor is the core of the systemMicroprocessor is the core of the system..

4. MICROPROCESSOR IMAGESMICROPROCESSOR IMAGES

5. Operation Types in a MicroprocessorOperation Types in a Microprocessor
All of the operations of the microprocessor can beAll of the operations of the microprocessor can be
classified into one of three types:classified into one of three types:
- Microprocessor Initiated OperationsMicroprocessor Initiated Operations
- Internal OperationsInternal Operations
- Peripheral Initiated OperationsPeripheral Initiated Operations

6. Microprocessor ArchitectureMicroprocessor Architecture
The Microprocessor can be programmed to performThe Microprocessor can be programmed to perform
functions on given data by writing specific instructionsfunctions on given data by writing specific instructions
into its memory.into its memory.
The microprocessor reads one instruction at a time,The microprocessor reads one instruction at a time,
matches it with its instruction set, and performs thematches it with its instruction set, and performs the
data manipulation specified.data manipulation specified.
The result is either stored back into memory orThe result is either stored back into memory or
displayed on an output device.displayed on an output device.

7. Pin Diagram Of 8085 MicroprocessorPin Diagram Of 8085 Microprocessor

8. Block Diagram Of MicroprocessorBlock Diagram Of Microprocessor

9. Four Important sections of MicroprocessorFour Important sections of Microprocessor
CU: Timing and Control UnitCU: Timing and Control Unit
ALU: Arithmetic and Logical UnitALU: Arithmetic and Logical Unit
Interface SectionInterface Section
Register SectionRegister Section

10. TIMING AND CONTROL UNITTIMING AND CONTROL UNIT
C.P.U is partitioned into A.L.U & C.U.C.P.U is partitioned into A.L.U & C.U.
It is the heart of a microprocessor , a hardware unit whichIt is the heart of a microprocessor , a hardware unit which
co-ordinate and control the various activities within andco-ordinate and control the various activities within and
outside the microprocessor by providing clock andoutside the microprocessor by providing clock and
control signals to the appropriate devices.control signals to the appropriate devices.
It controls the flow of the data between the processor &It controls the flow of the data between the processor &
memory & peripheralsmemory & peripherals..

11. ARITHMETIC & LOGIC UNITARITHMETIC & LOGIC UNIT
An arithmetic-logic unit (ALU) is also a hardware unitAn arithmetic-logic unit (ALU) is also a hardware unit
that carries out arithmetic and logical operations onthat carries out arithmetic and logical operations on
the operands in computer instruction words.the operands in computer instruction words.
The ALU includes storage places for input operands,The ALU includes storage places for input operands,
operands that are being added, the accumulated resultoperands that are being added, the accumulated result
(stored in an accumulato(stored in an accumulatorr), and shifted results.), and shifted results.
It performs arithmetic operations like addition,It performs arithmetic operations like addition,
subtraction, increment, decrement etc.subtraction, increment, decrement etc.
It also performs logical operations like AND, OR, XOR,It also performs logical operations like AND, OR, XOR,
NOT, Complement etc.NOT, Complement etc.

12. How ALU Works?How ALU Works?

13. Interface SectionInterface Section
This constitute several input and output hardware linesThis constitute several input and output hardware lines
through which the microprocessor can communicatethrough which the microprocessor can communicate
internally and also with external devices.internally and also with external devices.
This Section provide us : Address BusThis Section provide us : Address Bus
Data BusData Bus
Control BusControl Bus
Utility BusUtility Bus

14. ADDRESS BUSADDRESS BUS
An address bus is a computer bus (a series of linesAn address bus is a computer bus (a series of lines
connecting two or more devices) that is used to specifyconnecting two or more devices) that is used to specify
a physical address.a physical address.
The width of the address bus determines the amount ofThe width of the address bus determines the amount of
memory a system can address.memory a system can address.
It transfers the address of the location.It transfers the address of the location.
It is called uni-directional because it transfers addressIt is called uni-directional because it transfers address
from C.P.U to memoryfrom C.P.U to memory//I/OI/O devices only.devices only.

15. Address Bus Memory Capacity ChartAddress Bus Memory Capacity Chart
Address Bus Size Maximum RAMAddress Bus Size Maximum RAM
20 bits 1MB20 bits 1MB
24 bits 16MB24 bits 16MB
32 bits 4GB32 bits 4GB
36 bits 64GB36 bits 64GB
40 bits 1TB40 bits 1TB
44 bits 16TB44 bits 16TB

16. DATA BUSDATA BUS
A collection of wires in which data is transmitted fromA collection of wires in which data is transmitted from
one computer to another external devicesone computer to another external devices..
The data bus carries digital information.The data bus carries digital information.
The data bus is connected to the inputs of several gatesThe data bus is connected to the inputs of several gates
and to the outputs of several gates.and to the outputs of several gates.
This is also called bi-directional bus because informationThis is also called bi-directional bus because information
may flow on the bus wires in both directions.may flow on the bus wires in both directions.

17. Register SectionRegister Section
It consists of several 8-bitIt consists of several 8-bit//16-bit registers used for16-bit registers used for
temporary storage of data, information or address.temporary storage of data, information or address.
There are basically two types of registers available in aThere are basically two types of registers available in a
microprocessor : General Purpose Registersmicroprocessor : General Purpose Registers
Special Purpose RegistersSpecial Purpose Registers

18. Special & General Purpose RegisterSpecial & General Purpose Register
General purpose registers are used for temporary storageGeneral purpose registers are used for temporary storage
of data, address or address of data.of data, address or address of data.
There are 6 general purpose registers namely B, C, D, E,There are 6 general purpose registers namely B, C, D, E,
H, L.H, L.
Each of them is a 8-bit register.Each of them is a 8-bit register.
To hold 16 bit data, combination of two 8-bit registersTo hold 16 bit data, combination of two 8-bit registers
can be used.can be used.

19. All special purpose registers have some specificAll special purpose registers have some specific
functions.functions.
 Program Counter (PC)Program Counter (PC):: A 16-bit on chip register whichA 16-bit on chip register which
will store the address of the instruction to be executedwill store the address of the instruction to be executed
next.next.
 Accumulator (A)Accumulator (A): It is an 8-bit register which can hold: It is an 8-bit register which can hold
either source or destination data. Most of the arithmeticeither source or destination data. Most of the arithmetic
and logical instructions are performed w.r.t accumulator.and logical instructions are performed w.r.t accumulator.
 Stack Pointer (SP)Stack Pointer (SP):: It is a 16-bit on chip register used toIt is a 16-bit on chip register used to
access external stack as memory.access external stack as memory.
Special & General Purpose RegisterSpecial & General Purpose Register

20.  Flag RegisterFlag Register: It is an 8-bit register whose five bits are: It is an 8-bit register whose five bits are
defined as flag bits. The five flag bits can get modified asdefined as flag bits. The five flag bits can get modified as
a result of some arithmetic and logical operations.a result of some arithmetic and logical operations.
Special & General Purpose RegisterSpecial & General Purpose Register

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