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

Rep-string manipulation instruction-microprocessor, REP : Repeat Instructi...

REP : Repeat Instruction Prefix :- This instruction is utilized as a prefix to other instructions. The instruction in which the REP prefix is provided, is executed repetitively

Sbb-arithmetic instruction-microprocessor, SBB: Subtract  with Borrow  :- ...

SBB: Subtract  with Borrow  :- The subtract with borrow instruction subtracts the source operand and the borrow flag (CF) which might reflect the result of the past calculations,

Display triangular shape using stars, write an assembly program to display ...

write an assembly program to display triangular star like shape

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

Assembly language programs-microprocessor, Assembly Language Example Progra...

Assembly Language Example Programs We studied the entire instruction set of 8086/88, pseudo-ops and assembler directives. We have explained the process of entering an assembly

Avr, how to code

how to code

Boolean and comparison instructions, what will be the value of EAX after fo...

what will be the value of EAX after following instructions execute? mov bx, 0FFFFh and bx, 6Bh

Eax and ax register, MyLocation SDWORD 14 TheTest        SDWORD 8     mov ...

MyLocation SDWORD 14 TheTest        SDWORD 8     mov    eax,MyLocation     mov    ebx,TheTest     neg     eax,ebx     sub     eax,ebx Show exactly what lives in eax after executi

Dec-arithmetic instruction-microprocessor, DEC:  Decrement :- The decremen...

DEC:  Decrement :- The decrement instruction subtracts 1 from the contents of the particular memory location or register. All the conditions code flags except carry flag are affec

Efficient assembly language program, (1) Write a program that will: (a) dis...

(1) Write a program that will: (a) display "Enter Your Name:" (b) convert the entered name to Capital letters (if small), If any other character is entered, the program wil

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