What is ALE? Explain the functions of ALE in 8085.

Answer Posted / k. k. ghosh

8085 processor has 16 address lines for 16 bit address of a
memory location. Out of this 16 address lines 8 adress
lines are solely dedicated to transfer 8 higher order
address bits while the remaining lower order 8 bits of the
address are sent through another 8 lines multiplexed with
the 8 bit data lines. It is the control signal ALE to be
sent by the processor in appropriate time to indicate the
operation of this 8 bit multiplexed bus whether it will be
used to send the lower order 8 address bits or to send the
8 data bits. How it is indicated ? Making ALE control HIGH
the multiplexed 8 bit bus will act as address bus while
making ALE control LOW the same 8 bit multiplexed bus will
act as data bus. Thus, ALE = 1 makes the address latched
i.e. latch enable and ALE = 0 makes the adress bus disable
but making it data bus enable. In this sense, this 8 bit
bus better should be said as data bus.

Is This Answer Correct ?    245 Yes 22 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

With the help of an example explain how physical address is calculated?

544


how does the 8086 differ from the 8085 microprocessor?

565


Mention the addressing modes of 8085?

644


Explain the functions of ale in 8085?

596


How the register in the 8086 are grouped together?

523






What is 8251?

659


Which are sixteen bit registers of 8085?

580


Given a circuit, draw its exact timing response?

3231


What are the index registers in 8086?

627


How are time delays calculated in the 8085?

687


What are the functions of general purpose registers?

605


Mention what is the difference between microprocessor and microcontroller?

630


What is stack pointer in 8051 microcontroller?

639


Can single bit of a port be accessed in 8051?

634


Name the unit that controls the sequential execution of instructions?

576