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

Advantage of wrapping database calls into mts transactions, Advantage of wr...

Advantage of wrapping database calls into MTS transaction If database calls are complete within the context of a transaction, aborting the transaction will undo and changes that

Proof by contradiction - artificial intelligence, Proof by Contradiction - ...

Proof by Contradiction - Artificial intelligence So, both backward chaining andforward chaining have drawbacks. Another approach is to think regarding proving theorems by contr

Forward chaining, Forward Chaining: Now we have suppose we have a set ...

Forward Chaining: Now we have suppose we have a set of axioms that we know are true statements about the world. Whether we set these to each be an initial state of the segoal

Explain the advantages of object oriented analysis design, Advantages of Ob...

Advantages of Object oriented analysis design The OO approach inherently makes every object a standalone component which can be reused within specific stat problem domains we

Why does ethernet specify a minimum frame size, Why does Ethernet specify a...

Why does Ethernet specify a minimum frame size. Ethernet frame gives a minimum frame size of 46 bytes. Whereas a data field of zero byte is legal, this causes a problem. While

Eliminating hazards - computer architecture, Eliminating hazards of pipeli...

Eliminating hazards of pipeline -  computer architecture: We can delegate the work of eliminating data dependencies to the compiler, which can fill up in suitable number of NO

Illustrate the text area, specifies a form field where user can enter large...

specifies a form field where user can enter large amounts of text. In most respects, works like an field. It can have a name as well as a def

Capacity and performance of storage - computer architecture, Capacity: ...

Capacity: Raw capacity Total amount of stored information that a medium or storage device can hold is expressed as a quantity of bytes and bits (for example 10.4 megabyte

Define interrupts, Interrupts are signals which cause the CPU to suspend th...

Interrupts are signals which cause the CPU to suspend the currently executing program and transfer to a special program known as an interrupt handler. Interrupt handler determines

What is importance of ras and cas in sdram, What is importance of RAS and C...

What is importance of RAS and CAS in SDRAM? SDRAM acquires its address command into two address words. This uses a multiplex scheme to save input pins. The initial address word

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