Intel 8080 manual CS-------It

Models: 8080

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Silicon Gate MOS 8259

PROGRAMMABLE INTERRUPT CONTROLLER

• Eight Level Priority Controller

• Individual Request Mask

• Expandable to 64 Levels

Capability

 

• Single +5V Sup

 

• Programmable Interrupt

 

(No Clocks)

 

Modes (Algorithms)

 

• 28 Pin Dua

ckage

 

The 8259 handles up to eight vectored priority interrupts for the 8080A CPU. I

r up to 64 vectored priority

interrupts, without additional circuitry. It will be, packaged

in a 28-pin plasf

technology and requires a

single +5V supply. Circuitry is static, requiring no clock input.

 

 

The 8259 is designed to minimize the software and real time overhead in modes, permitting optimization for a variety of system requirements.

PIN CONFIGURATION

 

 

IR 0

 

 

 

4---IR 1

 

READ!

REQUEST

IR 2

 

LATCH

4 --- IR 3

INTERRUPT

WRITE

MASK

. -- IR 4

REQUESTS

LOGIC

REGISTER

4 --- IR 5

 

 

 

"' - IR6 "' - IR7

o

CS-------It

CASO~--.nI

CAS1 ....--....n

CAS 2 """ --- . nII

SP ~--.nII CONTROL

LOGIC

INT......----I

INTA --- . nI~INTERNALBUS

5-173

Page 245
Image 245
Intel 8080 manual CS-------It