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

Define frequency division - application of flip flops, Define Frequency Div...

Define Frequency Division - Application of Flip Flop? When the pulse waveform is applied to the clock input of a J-K flip-flop that is connected to toggle, the Q output is a s

Explain auto increment and auto decrement mode, Explain Auto increment and ...

Explain Auto increment and Auto decrement mode  The register is incremented or decremented after (or before) its value is used to access memory.  The address stored in the regi

What is the significance of the memory table ''screen'', What is the signif...

What is the significance of the memory table 'SCREEN'? At runtime, attributes for every screen field are stored in the memory table called 'SCREEN'.  We need not declare this

What is clr, What is CLR?  CLR is .NET equivalent of Java Virtual Mach...

What is CLR?  CLR is .NET equivalent of Java Virtual Machine (JVM). It is the runtime that changes a MSIL code into the host machine language code, which is then implemented a

Define seek time and latency time, Define seek time and latency time. ...

Define seek time and latency time.  The time taken by the head to move to the appropriate cylinder or track is known as seek time. Once the head is at right track, it must wai

Enumerate in detail about image scanners, Enumerate in detail about Image S...

Enumerate in detail about Image Scanners Drawings, graphs, colour and black-and-white photos, or text can be stored for computer processing with an image scanner by passing an

Define the register length, Q. Define the Register Length? Register Le...

Q. Define the Register Length? Register Length: Asignificant characteristic related to registers is length of a register. Generally the length of a register is dependent on it

Desirable choice for the partitioning element in quick sort, A desirable ch...

A desirable choice for the partitioning element in quick sort is First element of the list.

What is dynamic random access memory, Q. What is Dynamic Random Access Memo...

Q. What is Dynamic Random Access Memory? RAM technology is divided into 2 technologies: Static and dynamic. A dynamic RAM (DRAM) is made with cells which store data as charge o

Define the role of organizationin computer architecture, Define the role of...

Define the role of organizationin computer architecture The organization is the set of resources that realizes the architecture which include the CPU, the memory and I/O contro

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