General bus operation-microprocessor, Assembly Language

General Bus Operation

The 8086 has a joined data and address bus commonly referred to as a time multiplexed address and data bus. The major reason behind  multiplexing address and data  over the similar pins is the  maximum utilization of processor pins and it facilitates the use of 40 pin standard  DIP package. The bus may be de-multiplexed by using a few transceivers and latches, whenever required. In the following text, a general bus operation cycle is described.

Mainly all the processor bus cycles contain of at least 4 clock cycles. These are referred to as T4, T3, T2 and T1• the address is transmitted by the processor during T1. It is present on the bus just for 1 cycle. During T2, for example- in the next cycle, the bus is tristated for altering the direction of bus for the following data read cycle. The data transfer takes place during T4and T3. In case, an addressed device is slow and shows

'NOT READY' status the wait states Tware inserted between T3 and T4. During wait periodthese  all clock states are known wait states (Tw),idle states (Ti),  or inactive  states. The processor utilize these cycles for internal housekeeping.  The  address  latch  enable  (ALE)  signal  is  emitted  during  T,  by  the bus controller (maximum mode) orthe  processor (minimum mode) depending upon the status of the MN/MX input. The negative edge of this ALE pulse is utilized to separate the address and the status or data information. In maximum mode, the status lines S0, S1 and S2 are utilize to indicate the type of operation as described in the pin description of this unit. Status bits BHE/s7 are multiplexed with BHE and signalhigher order address bits. Address is valid during T1 while the status bits S3  to S7  are valid during T2  through T4. The Figure2.7 shows a general bus operation cycle of 8086.

 

1520_general bus.jpg

Posted Date: 10/10/2012 2:49:42 AM | Location : United States







Related Discussions:- General bus operation-microprocessor, Assignment Help, Ask Question on General bus operation-microprocessor, Get Answer, Expert's Help, General bus operation-microprocessor Discussions

Write discussion on General bus operation-microprocessor
Your posts are moderated
Related Questions
Machine Coding the Programs So far we have describe five programs which were  written  for hand coding  by a programmer. In this, we will now have a deep look at how these prog

Using the following table as a guide, write a program that asks the user to enter an integer test score between 0 and 100. The program should display the appropriate letter grade.

Can any one assist me with this program. I am not efficient with assembly language and I need assistance badly. I am not asking anyone to do my work I just need help step by step

RET : Return from the Procedure:- At each CALL instruction, the register IP and register CS of the next instruction is pushed to stack, before the control is transferred to the

How is bob different from johnny in the outsiders

I was wondering if you guys could offer me some advice and help on how to proceed - not answers- for a homework problem I am attempting. I am currently working on a "bomb" project

8088  Timing System Diagram The 8088 address/data  bus is divided  in 3 parts (a) the lower 8 address/data  bits, (b) the middle 8 address bits, and (c) the upper 4 status/

CANI GET HELP WRITTING THIS CODE

Write an assembly language program that defines symbolic constants for all seven days of the week

do you type assembly code or machine code instructions like b8 0100000 to add to register EAX straigt onto dos command line or do you have to same in a file and what extension woul