Draw and elucidate the block diagram 8259, Computer Engineering

Draw and elucidate the block diagram of programmable interrupt controller 8259.

The 8259A adds 8 vectored priority encoded interrupts to microprocessor. It can be expanded to 64 interrupt requests by employing one master 8259A and 8 slave units. CS and WR should be decoded. Other connections are direct to microprocessor. 

Pins D7 - D0: bidirectional data connection, IR7 - IR0: Interrupt request, used to request an interrupt and connect to a slave in a system with multiple 8259A.

WR :-Connects to a write strobe signal (upper or lower in a 16 bit system) ,  RD :- Connects to IORC signal ,  INT :- Connects to INTR pin on the microprocessor from master and is connected to a IR pin on a slave  and  INTA :- Connects to INTA pin on the microprocessor.  In a system only master INTA signal is connected A0:- Selects different command words with in 8259A, CS: - Chip select - enables 8259A for control andprogramming, SP/EN: - Slave Program (1 for master, 0 for slave)/Enable Buffer (controls data bus transceivers in a large microprocessor based system when in buffered mode) and CAS2-CAS0:- Used as outputs from master to the slaves in cascaded systems. 

 

2345_micro.png

Posted Date: 8/20/2013 2:35:02 AM | Location : United States







Related Discussions:- Draw and elucidate the block diagram 8259, Assignment Help, Ask Question on Draw and elucidate the block diagram 8259, Get Answer, Expert's Help, Draw and elucidate the block diagram 8259 Discussions

Write discussion on Draw and elucidate the block diagram 8259
Your posts are moderated
Related Questions
WML & WML Script 1. How to call a WML Script from a WML Page? 2. Write a brief note on WML Script Operators and Expressions. 3. Write brief notes on WML Script Statements

To execute sparse matrix dynamically, Which data structure is used Linked List data structure is used to execute sparse matrix dynamically

Make a page translation table the meets the requirements of the virtual memory system given below.  Suppose page (and frame) sizes of 20 with pages 0 by 3 in logical memory and fra

Magento uses PHP as a web server scripting language and the MySQL Database. The data model is based on the Entity-attribute-value model that stores data objects in tree structures,

Explain Time Division Switching. Time Division Switching: A switching component can be shared at the same time with number of active speech circuits. It is the principle of

How does the Xml Serializer work?  What ACL permissions does a process using it require?   Xml Serializer needs write permission to the system's TEMP directory.

Question (a) A 500 MHz Pentium III processor takes 2 ms to run a program with 200,000 instructions. A 300 MHz UltraSparc processor takes 1.8 ms to run the same program with 23

Breadth First Search: Given a set of operators o1, ..., on in a breadth first search, every time a new state is reached, an action for each operator on  s  is added to the bot

Reflexes - artificial intelligence: If an agent decides upon and executes an action in response to a sensor input without consultation of its world, then this can be considere

What is the function of the correction system? The correction system handles changes to internal system components. Like as objects of the ABAP/4 Dictionary.