Illustrate about 8259, Computer Engineering

Assignment Help:

Illustrate about 8259

8259A adds 8 vectored priority encoded interrupts to the microprocessor. We can expand it to 64 interrupt requests by using one master 8259A and 8 slave units. CS and WR should be decoded. Other connections are direct to microprocessor. 

Pins D7 - D0: the 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 the master and is connected to an 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 the 8259A, CS: - Chip select - enables 8259A for programming and control, 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 the master to slaves in cascaded systems. 

 

2064_micro.png

                                                            Figure: 8259 Block Diagram


Related Discussions:- Illustrate about 8259

Disc shapes and diameters - computer architecture, Disc shapes and diameter...

Disc shapes and diameters:     A Mini-CD is 8 centimeters in diameter. The digital data on a CD start at the center of the disc and proceeds toward the edge, whi

Define range which a normalised mantissa can signify, Now let's define rang...

Now let's define range which a normalised mantissa can signify. Let's presume that our present representations has normalised mantissa so left most bit can't be zero so it has to b

Authentication system differ from a firewall in functioning, How does an au...

How does an authentication system differ from a firewall in functioning?   Authentication vs. firewall User Authentication and Authorization A significant advanced fi

Define restoring method, Define restoring method? The hardware method j...

Define restoring method? The hardware method just explained is called the restoring method. The reason for this name is that the partial reminder is restored by adding the divi

Example of finding cross points and switches, For a non blocking crossbar c...

For a non blocking crossbar configuration, taking N as the number of subscribers, there will be               number of cross points and _             number of switches for est

Anu, write a program to find the area under the curve y=f(x) between x=a an...

write a program to find the area under the curve y=f(x) between x=a and y=b integrate y=f(x) between the limits of a and b. the area under a curve between two points can be found b

What are the roll and page areas, What are the roll and page areas? Ro...

What are the roll and page areas? Roll and page areas are SAP R/3 buffers used to kept user contexts (process requests).  The SAP dispatcher assigns procedure requests to work

Support concurrent programming, Q) a.Define the programming-language featur...

Q) a.Define the programming-language features that are required to properly  support concurrent programming? b. What support do these features need from the operating system?

Two ethernet switches sw1 and sw2 , Six machines H1, H2, ..., H6 are linked...

Six machines H1, H2, ..., H6 are linked by two Ethernet switches SW1 and SW2 as given below. Both switches have four ports drawn. The port numbers are as indicated. Suppose the two

Characteristics of input- output channels, Q. Characteristics of input- out...

Q. Characteristics of input- output channels? The I/O channel represents an extension of DMA concept. An I/O channel has ability to execute I/O instructions that gives complete

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