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, 2. Write a program to separate out positive and negative numbers f...

2. Write a program to separate out positive and negative numbers from a given series of 16-bit hexadecimal numbers.

Program to add contents in memory-machine level programs, Example : Add th...

Example : Add the contents of the 2000H: 0500H memory location to contents of 3000H: 0600H and store the result in 5000H: 0700H. Solution : Unlike the past example progra

Pc bus and interrupt system-microprocessor, PC Bus and Interrupt System ...

PC Bus and Interrupt System The PC Bus utilized a bus controller, address latches, and data transceivers (bidirectional data buffers). 1) Bus controller : ( Intel 8288 Bus

Icwi-microprocessor, The definitions of the bits in ICWI are following: ...

The definitions of the bits in ICWI are following: Always set to the value 1. It directs the received byte to ICWI as oppose to OCW2 or OCW3. Which also utilize the even addr

Convert from C to 8086 assembly language, Trying to convert small programs ...

Trying to convert small programs from C to 8086 assembly language using emu 8086 emulator. I converted to low level C, but struggling with converting to the Assembly language.

Program to perform one byte bcd addition-assembly program, Program : Write...

Program : Write a program to perform a one byte BCD addition. Solution : It is consider that the operands are in BCD form, but the CPU considers it as hexadecimal and acco

DIV subroutine, I need a division subroutine. Asks for two inputs, then dis...

I need a division subroutine. Asks for two inputs, then displays the inputs and shows the answer with a remainder. Mine isnt displaying the inputs correctly.

8088 associated with 8259 a-microprocessor, For an 8088 the 2 addresses lin...

For an 8088 the 2 addresses linked with an 8259A are normally consecutive, and the AO line is associated to the AO pin, but because there are just 8 data pins on the 8259A and the

Flag register-microprocessor, Flag Register : 8086 has a 16-bit flag r...

Flag Register : 8086 has a 16-bit flag register which is divided into 2 parts, viz. (a)machine control flagsand (b)condition code or status flags. The condition code flag regi

String manipulation instruction-microprocessor, String Manipulation Instruc...

String Manipulation Instruction A series of words or data bytes are available in memory at consecutive locations, to be mention to individually or collectively, are known as by

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