Intel mcs-48 manual Ii,D, Sgs

Models: mcs-48

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inter

8214/3214*

PRIORITY INTERRUPT CONTROL UNIT

8 Priority Levels

Fully Expandable

Current Status Register

High Performance (50 ns)

Priority Comparator

• 24·Pin Dual In·LlnePackage

The Intel~ 8214 is an 8·levelpriority Interrupt control unit (PICU) designed to simplify interrupt·drivenmicrocomputer systems.

The PICU can accept 8 requesting levels; determine the highest priority. compare this priority to a software controlled current status register and issue an interrupt to the system along with vector information to identify the service routine.

The 8214 is fully expandable by the use of open collector interrupt output vector information. Control signals are also provided to simplify this function.

The PICU is designed to support a wide variety of vectored interrupt structures and reduce package count in Interrupt· driven microcomputer systems.

'Note:The specifications for the 3214 are Identical with those for the 8214.

PIN CONFIGURATIONLOGIC DIAGRAM

IE> ElR

·0

Ees

 

 

 

.,

I1!>ETlG--

 

.,

Vee

 

 

 

 

~ Ra

REQUEST ACTIVITY

 

 

A;

I!!>

R;

 

SGS

A,

[!D

R,

 

I!!>

R,

 

'NT

R,

I!!>

;;:;

 

elK

A,

~

"-

 

 

8214

~

As

 

 

~ R;

 

'NTE

R,

 

A;;

A,

I:!>

B,

 

 

 

 

A,

A,

ID

s:;

 

A,

R,

II>

B,

 

 

 

[D SGS

PRIOR lTV

ElA

ENLG

l?D

EcS

COMPARATOR

 

 

 

 

GNO

ETLG

 

 

 

 

PIN NAMES

CC>'NTE-----------------

~

 

OC> ~--------------------------~

INPUTS

 

 

 

 

 

 

RO-A?

REQUEST LEVELS IR7 HIGHEST PRIORITY)

 

 

80-82

CURRENT STATUS

 

 

 

iGi

STATUS GROUP SELECT

 

 

 

ECi

ENABLE CURRENT STA'JUS

 

 

INTE

INTERRUPT ENABLE

 

 

 

ill

CLOCK UNT F·FI

 

 

 

ELA

ENABLE lEVEL READ

 

 

 

ETLG

ENABLE THIS LEVEL GROUP

 

 

.....,

REQUEST LEvl:LS

}-OPEN

 

 

OUTPUTS:

 

 

 

 

M

INTEARUPT(ACT. LOW)

COLLECTOR

 

 

ENLO ENABLE NEXT LEVEL GROUP

A.[D

iI,[D

A,11!>

8-34

AFN·00210A-ol

Page 295
Image 295
Intel mcs-48 manual Ii,D, Sgs