Searching \ for 'MCLR rise time issues' 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/timers.htm?key=time
Search entire site for: 'MCLR rise time issues'.

Truncated match.
PICList Thread
'MCLR rise time issues'
1998\11\05@173255 by Dale Wescombe

flavicon
face
Can anyone please help me. I have a problem using a pic17c44 where if I
don't delay the rise of MCLR by about 2 seconds on power up, the program
freezes and won't start. This seems illogical to me and I'm assured that
the software is correct. Any suggestions?????????????????
Thanks in advance
Dale

1998\11\05@180852 by Tony Nixon

flavicon
picon face
Dale Wescombe wrote:
>
> Can anyone please help me. I have a problem using a pic17c44 where if

Power supply problems, slow rise, spikes etc, bus contention

External influences like relying on reading info from devices which have
not initialized themselves.

Unintended Port Interrupt generated while powering up.

Can't think of any more, it's Friday..


--
Best regards

Tony

Multimedia 16F84 Beginners PIC Tools.

http://www.picnpoke.com
Email spam_OUTpicnpokeTakeThisOuTspamcdi.com.au

1998\11\06@051644 by paulb

flavicon
face
Dale Wescombe wrote:

> Can anyone please help me. I have a problem using a pic17c44 where if
> I don't delay the rise of MCLR by about 2 seconds on power up, the
> program freezes and won't start.

 This sounds very much as if the Vcc risetime of the regulated supply
is far too slow.

 Too much capacitance perhaps?  Or just use a reset circuit and live
with it.
--
 Cheers,
       Paul B.

1998\11\06@092132 by Ryan Miller

flavicon
face
We've always used the brownout protection circuit mentioned in the data book
for our 17C44s and 16C73s and have never had any problems. It uses three
resistors and a PNP transistor to hold the MCLR low until VDD is above a set
voltage. Take a look at it; it's in the Reset section of the databook.

Ryan

>
> Can anyone please help me. I have a problem using a pic17c44 where if I
> don't delay the rise of MCLR by about 2 seconds on power up, the program
> freezes and won't start. This seems illogical to me and I'm assured that
> the software is correct. Any suggestions?????????????????
> Thanks in advance
> Dale
>

1998\11\20@070152 by Tony Nixon

flavicon
picon face
Dale Wescombe wrote:
>
> Can anyone please help me. I have a problem using a pic17c44 where if

Power supply problems, slow rise, spikes etc, bus contention

External influences like relying on reading info from devices which have
not initialized themselves.

Unintended Port Interrupt generated while powering up.

Can't think of any more, it's Friday..


--
Best regards

Tony

Multimedia 16F84 Beginners PIC Tools.

http://www.picnpoke.com
Email .....picnpokeKILLspamspam@spam@cdi.com.au

1998\11\20@070828 by Dale Wescombe

flavicon
face
Can anyone please help me. I have a problem using a pic17c44 where if I
don't delay the rise of MCLR by about 2 seconds on power up, the program
freezes and won't start. This seems illogical to me and I'm assured that
the software is correct. Any suggestions?????????????????
Thanks in advance
Dale

More... (looser matching)
- Last day of these posts
- In 1998 , 1999 only
- Today
- New search...