Pin functions of 8086-microprocessor, Assembly Language

Assignment Help:

Pin functions for the minimum mode operation of 8086 are following:

1) M/I/O -Memory/IO: This is a status line logically equivalent to S2 in maximum mode. When it is low, it denotesthe CPU is having an I/O operation, and when it is high, it denotes that the CPU is having a memory operation. In the previous T4this line becomes active and remains active till last T4 of the current cycle. During local bus this is tristated "hold acknowledge".

2) INTA-interrupt Acknowledge: This signal is utilized as a read strobe for interrupt acknowledge cycles.  In other terms, when it goes low, this means that the processor has accepted the interrupt. It is active low during T3, T2 and Tw of each interrupt acknowledge cycle.

3) ALE-Address  Latch  Enable: This  output  signal  indicates  the  availability  of  the  valid  address  on  the address/data lines, and is associated to latch enable input of latches. This signal is active high and is never tristated.

4) DT/R  -Data  Transmit/Receive: This output is utilized to decide the direction of data flow through the transreceivers (bidirectional  buffers). When the processor sends data, this signal is high and when the processor is receiving data, this signal is low. Logically, this is corresponding toS1 inmaximum mode. Its timing is the similar as M/I/O. This is tri stated during 'hold acknowledge'.

5) DEN-Data Enable: This signal denote the availability of valid data over the address/data lines. It is utilized to enable the Trans receivers (bidirectional buffers) to separate the data from the multiplexed address/data signal. It is active from the centre of T2 until the middle of T4.

DEN is tristated during 'hold acknowledge' cycle. HLDA-Hold/Holdand HOLD Acknowledge: When the HOLD line go high, it denote to the processor that another master is requesting the bus access. , in the middle of the next clock cycle after receiving the HOLD request the processor is use the hold acknowledge signal on HLDA pin after completing the current bus (instruction)  cycle. At the same time, the processor floats the control lines andlocal bus. When the processor detects the HOLD line low then it lowers the HLDA signal. HOLD is asynchronous input and it should be synchronized externally.

 


Related Discussions:- Pin functions of 8086-microprocessor

Program, assembly language program to find larges number in an array

assembly language program to find larges number in an array

Signal descriptions of 8086-microprocessor, Signal descriptions of 8086 : ...

Signal descriptions of 8086 : described below are common for the maximum andminimum mode bothdata lines AD15 -AD0: These are the time multiplexed andmemory I/O address. Addre

The 486, The 486 Introduced in the year 1989 the 80486 did not feature ...

The 486 Introduced in the year 1989 the 80486 did not feature any radically new processor technology. Instead, it joints a 386 processor, a cache memory controller and a math c

Program to accept the input from user, Write an assembly language program t...

Write an assembly language program that will: accept keyboard input of a positive integer value N; compute the sum S= 1+ 2 + 3 + ... + N; print (output) the computed su

input and output, Description: LC3 allows input from keyboard and out...

Description: LC3 allows input from keyboard and output to display on the screen. This lab will exercise the input/output capability using LC-3 Assembly language. Procedure

Dma hardware (8237 dmac)-microprocessor, DMA Hardware (8237 DMAC) : ...

DMA Hardware (8237 DMAC) :   1)Processor contain HOLD/HOLD Acknowledge lines to interact with 8237 o   DMAC can achieve control of ISA bus by asserting HOLD o   P

Procedures, How to define procedures?

How to define procedures?

Flowchart for the sequence of 8251-microprocessor, Flowchart for the sequen...

Flowchart for the sequence of 8251 Whether the control, mode or sync character register is selected depends on the accessing sequence.  A flowchart of the sequencing is given i

Not-logical instruction-microprocessor, NOT : Logical Invert: The NOT inst...

NOT : Logical Invert: The NOT instruction complements (inverts) the contents of an a memory location or operand register bit by bit. The instance are as following: Example :

Progframmw, write a programme the addition two 3*3 matrix and stored in fro...

write a programme the addition two 3*3 matrix and stored in from list

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd