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
State about the Data Glove  Data glove is used to grasp a "virtual" object. The glove is constructed with a series of sensors that detect hand and finger motions. Electromagnet

Explain Tabulation Method for simplifying k maps? The Tabulation Method (QUINE-McCLUSKEY MINIMIZATION) An expression is represented in the canonical SOP form if not

What is race around condition? Ans: Race Around Condition:- Jn Kn Q(n+1) output   0 1 0 1   0 0

1. In an ASCII editor, make an empty text file with the extension .ord. 2. Save the file in the Dat folder of the project. 3. Click To o l s > G UI R e c o r d O p t i o n s

Maximum channel utilization in a LAN is defined by frame time (t f ) and propagation time (t p ). It is defined by (A) t p /t f (B) t f /t p  (C) 1 + (t f /t p )

Can the operand expression in an ORG statement contains forward references? If so, outline how the statement can be processed in a two-pass assembly scheme. ORG that is origin

Designed, developed, tested and documented the demo created for NPBlox framework. NPBlox framework is a framework which enabled developers to create CLI/WEB/SNMP interfaces for

What is EDO RAM A minor modification to the structure of the DRAM changes the device into an EDO (extended data output) DRAM device. In EDO memory, any memory access, including

Consider  a  collection  class  that  is  similar  to  the ArrayList  class,  except  that  elements  are sorted in a certain order. We will call this class SortedArrayList. This c

Determine the term Queries-DBMS Queries most commonly allow information to be retrieved from tables. As the information is often spread across numerous tables, queries allow it