Archive for April 2013

Memory mapped input-output

In this method, an I/O device is treated as a memory location. The microprocessor uses 16- bit address to identify and I/O device. Thus the memory map is shared between memory and I/O devices.
Memory-mapped I/O uses the same to address both memory and I/O devices. The memory

programmable and nonprogrammable i/o ports

Non-programmable I/O Port: It behaves as an input port if it has been designed and connected in input mode. Similarly a port connected in output mode acts as an output port. Example: INTEL 8212 Programmable I/O Port: It can be programmed to act either as an input

Define coprocessor and need of coprocessor

Coprocessor is a single chip built for performing scientific computations at high speed. This chip is a companion to the original or host processor. A coprocessor is a computer processor used to supplement the functions of the primary processor (the CPU). It can be used to perform various operations. It is used to perform specialized function.
 The general-purpose processors such as 8086 or 8085 are not optimized to do arithmetic manipulations, CRT display manipulation and word processing. Hence we go for a coprocessor, which is capable of doing dedicated functions (Special Operations) to increase the overall execution speed of larger systems. 

Coprocessor is connected in parallel with the main processor, and they operate on the same buses with the same instruction byte stream.

Latch and Clock pulse

Latch: A bistable circuit that is set and reset by appropriate input signals. An electronic circuit that records the status of a signal until it is reset. A latch is a kind of bistable multivibrator, an electronic circuit which has two stable states and thereby can store one bit of information. Today the word is mainly used for simple transparent storage elements.

Clock Pulse: A synchronization signal provided by a clock. A periodic signal used for

Packed BCD and Unpacked BCD

Packed BCD: Packed BCD Numbers are stored in two digits to a byte, in 4 bit groups referred to as nibbles. ALU is capable of performing only binary addition and subtraction, but

Control and status signal in 8085

ALE , RD, WR, IO/M, S1, S2
ALE-Address Latch Enable
RD – Read Control Signal
WR – Write Control Signal
IO/M - To specify I/O or memory operation
S1 , S2 – Status signals

Define Real Time System

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”.

Use of microprocessor in medical instrumentation

1. Patient Monitoring in Intensive Care Unit.
2. Pathological Analysis and the measurement of parameters like blood pressure and temperature.
3. Measurement of heart activity.
4. Ultrasound Processing unit.
5. MRI scanning
6. CT scanning etc.

Assembly Language, Machine Language

Assembly Language: It  is human understandable language that is written by language. It is a medium of communication with a computer in which programs are written in mnemonics. Binary instructions are given abbreviated names called mnemonics, which form

System Bus, Address Bus, Data Bus

System Bus: The System bus is a communication path between the microprocessor and peripherals. It is nothing but a group of wires to

What is CPU and its uses

CPU is a heart of the computer. Central processing Unit controls the operation of the computer. In a microcomputer the CPU is a microprocessor. The CPU fetches binary coded instructions from memory, decodes the instructions into a series of

Microprocessor as programmable device

Microprocessor is a multipurpose, programmable, clock-driven, register based electronic device that reads binary instructions from a storage device called memory, accepts binary data as

Difference between hardware and software

The physical components of the system i.e. computer are called Hardware. Group of programs is called software.
Program is set of instruction that is used to perform a particular instruction.

1. Now we are taking example of a PC.

Define Microprocessor

Microprocessor is a multipurpose, programmable, clock-driven, register based electronic device that reads binary instructions from a storage device called memory,


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