Searching \ for '[PIC]: Multiple IRQ'S ?' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'Multiple IRQ'S ?'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: Multiple IRQ'S ?'
2000\05\30@060801 by Kbek Tony

flavicon
face
Hi,
What's the 'best' way to interface several external irq requests ?
PortB change feature seems 'no-go', OR'ing several irq's
to the INT pin seems doable ( and then poll which one it was )
but potentially dangerous ( strong possibility of missing one ).

Any suggestions ?

/Tony


Tony KŸbek, Flintab AB            
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
E-mail: spam_OUTtony.kubekTakeThisOuTspamflintab.com
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓ

2000\05\30@061628 by Michael Rigby-Jones

flavicon
face
If the interrupt signal is likely to be too short to be able to poll in the
ISR, then maybe you could use something like an SR flip flop for each IRQ.
The incomming interrupt would set the output of the flip flop which can be
diode OR'ed to the int pin.  The ISR would have the responsibility of
clearing each flip flop after servicing its interrupt.  With a bit of
cunning (and a resistor or two) you could use the same PIC pin to read and
reset the flip flop.

Mike

> {Original Message removed}

2000\05\31@043053 by Kbek Tony

flavicon
face
Hi,

Mike wrote:
>If the interrupt signal is likely to be too short to be able to poll in
the
>ISR, then maybe you could use something like an SR flip flop for each
IRQ.
>The incomming interrupt would set the output of the flip flop which can
be
>diode OR'ed to the int pin.  The ISR would have the responsibility of
>clearing each flip flop after servicing its interrupt.  With a bit of

Yes that was my idea.

>cunning (and a resistor or two) you could use the same PIC pin to read
and
>reset the flip flop.

Hmm this got me stumbled, how ? cant figure out a circuit that would
work
using the same pin as input/reset.
Would You care to elaborate ?


/Tony

Tony KŸbek, Flintab AB            
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓ
E-mail: .....tony.kubekKILLspamspam@spam@flintab.com
ÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓÓ

2000\05\31@090859 by Alok Dubey

flavicon
face
use the good old obselete 8086 based interrupt ctlr.. i forgot the number..
but this is essentially what i did.
alok


{Original Message removed}


'[PIC]: Multiple IRQ'S ?'
2000\06\01@153537 by Keith Causey
flavicon
face
The generic number is 8259 and it's gotten a facelift. There is a 28 j-lead
package of this device that has a 12mhz rating from Future Electronics.

use the good old obselete 8086 based interrupt ctlr.. i forgot the number..
but this is essentially what i did.
alok


{Original Message removed}

More... (looser matching)
- Last day of these posts
- In 2000 , 2001 only
- Today
- New search...