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

What is secondary list, What is secondary list? It permits you to enha...

What is secondary list? It permits you to enhance the information presented in the basic list.  The user can, for example, select a line of the basic list for which he require

Operating systems, Consider the state transition diagram of Figure 3.9b . S...

Consider the state transition diagram of Figure 3.9b . Suppose that it is time for the OS to dispatch a process and that there are processes in both the Ready state and the Ready/S

Using the memory map design an absolute decoding circuit, Using the memory ...

Using the memory map below; design an absolute decoding circuit.   The technique is to spot the differences between the start and stop of each device. The Ram chip has the follow

Define cache line, Define cache line. Cache block is used to refer to a...

Define cache line. Cache block is used to refer to a set of contiguous address location of some size. Cache block is also referred to as cache line.

What is the significance of technical settings, What is the significance of...

What is the significance of Technical settings (specified while creating a table in the data dictionary)?  By specifying technical settings we can handle how database tables ar

First-order logic - artificial intelligence, First-Order Logic We, as h...

First-Order Logic We, as humans, have always prided ourselves on our ability to think things through for this reason things are out and come to the only conclusion possible in

What is actor, What is actor? An actor is a direct external user of a s...

What is actor? An actor is a direct external user of a system. Every actor shows objects that behave in a particular way towards systems. Actors are directly linked to system.

Returns and procedures definitions in 8086, Q. Returns and Procedures defin...

Q. Returns and Procedures definitions in 8086? 8086 microprocessor supports RET and CALL instructions for procedure call. CALL instruction not only branches to indicate address

Write shorts notes on digital signature, Write shorts notes on Digital Si...

Write shorts notes on Digital Signature. This method is used to authenticate the sender of a message. For sign a message, the sender encrypts the message by using a key ident

Explain batch operating systems, Explain Batch operating systems. Batc...

Explain Batch operating systems. Batch operating systems : A batch is a sequence of jobs. Such batch is submitted to batch processing operating systems moreover output would s

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