Searching \ for ' Multiple uCs sharing same clock' 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=clock
Search entire site for: 'Multiple uCs sharing same clock'.

No exact or substring matches. trying for part
PICList Thread
'[PICLIST] Multiple uCs sharing same clock'
2001\08\16@093414 by Tobie Horswill

flavicon
face
Hi, I was wondering if there were any quirks that I should know of if I want
to drive several PICs from the same clock ? A 20MHz ceramic resonator in
this particular case. Can I simply run all the PICs clock inputs in parallel
on the same resonator ? Somehow this doesn't feel wright, perhaps I should
"regenerate" the clock at TTL level first ? I recall a circuit that did
something like this on the MicroChip site but couldn't track it down...

regards,
_____________________
Tobie Horswill
Ex Machina
103, rue Dalhousie
Quibec (Quibec) CAN
G1K 4B9

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2001\08\16@095924 by zantos

flavicon
face
I put the resonator on one device and then the OSC2 (out) to the first
deivce OSC1 (in) and it's OSC2 (out) to the second device OSC1(in).... and
so on. This worked for me.
HTH

{Original Message removed}

2001\08\16@100220 by zantos

flavicon
face
I put the resonator on one device and then the OSC2 (out) to the first
device OSC1 (in) and it's OSC2 (out) to the second device OSC1(in).... and
so on. This worked for me. Only problem is you cannot isolate to test you
need all devices in.
HTH

{Original Message removed}

2001\08\16@101045 by Jeff DeMaagd

flavicon
face
----- Original Message -----
From: Tobie Horswill <spam_OUTthorswilTakeThisOuTspamEXMACHINA.QC.CA>

> Hi, I was wondering if there were any quirks that I should know of if I
want
> to drive several PICs from the same clock ? A 20MHz ceramic resonator in
> this particular case. Can I simply run all the PICs clock inputs in
parallel
> on the same resonator ? Somehow this doesn't feel wright, perhaps I should
> "regenerate" the clock at TTL level first ? I recall a circuit that did
> something like this on the MicroChip site but couldn't track it down...

I have been using a self-contained full and half can oscillators (they
generate clock just by applying power to it) and fanning it out to multiple
pics with good success.  Not for every situation but they all use the same
clock just fine.

Jeff

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2001\08\16@102054 by Spehro Pefhany

picon face
At 09:32 AM 8/16/01 -0400, you wrote:
>Hi, I was wondering if there were any quirks that I should know of if I want
>to drive several PICs from the same clock ? A 20MHz ceramic resonator in
>this particular case. Can I simply run all the PICs clock inputs in parallel
>on the same resonator ? Somehow this doesn't feel wright, perhaps I should
>"regenerate" the clock at TTL level first ? I recall a circuit that did
>something like this on the MicroChip site but couldn't track it down...

If there is much distance (more than an inch or two with ground plane)
between the clock pins, it might be wise to buffer the clock output pin
using a single gate buffer. Here is one possbility, most of the
manufacturers have something similar:

http://www.fairchildsemi.com/ds/NC/NC7S32.pdf

One input to the clock OUT pin from the PIC with the crystal, decrease
the capacitor value by the input capacitance of the 7S32, and connect the
other input of the S32 to 0V. The output of the gate drives the other
PIC(s) using the external clock circuit (clock OUT open, input to clock IN).

If you have the room, a 74HC32 will be a bit cheaper (0.19 vs. 0.39 US/100pcs)

Or, use a packaged oscillator, which is guaranteed to work, as someone just
mentioned.

Best regards,
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Spehro Pefhany --"it's the network..."            "The Journey is the reward"
.....speffKILLspamspam@spam@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


'[EE]: (repost) Multiple uCs sharing same clock'
2001\08\16@102508 by Tobie Horswill

flavicon
face
repost wrong tag ...

Hi, I was wondering if there were any quirks that I should know of if I want
to drive several PICs from the same clock ? A 20MHz ceramic resonator in
this particular case. Can I simply run all the PICs clock inputs in parallel
on the same resonator ? Somehow this doesn't feel wright, perhaps I should
"regenerate" the clock at TTL level first ? I recall a circuit that did
something like this on the MicroChip site but couldn't track it down...

regards,
_____________________
Tobie Horswill
Ex Machina
103, rue Dalhousie
Quibec (Quibec) CAN
G1K 4B9

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


'[PICLIST] Multiple uCs sharing same clock'
2001\08\16@103345 by Tobie Horswill

flavicon
face
Hey! many thanks to all. Geez this list is great! I did'nt even have time to
repost my first request that I already had 3 answers...


________________________________
Tobie Horswill
Ex Machina, Quibec (Quibec) CANADA
thorswilspamKILLspamexmachina.qc.ca

{Original Message removed}

2001\08\17@110922 by dr. Imre Bartfai

flavicon
face
Hi,

I did it in a following way: I set up a PIC as a master, connecting the
resonator as it would be alone. Than, I lead the CLKOUT to another PIC's
CLKIN. It worked.

I hope this helps.

Imre


+-----------------------------------------------------------------------+
| The information transmitted is intended only for the person or entity |
| to which it is addressed and may contain confidential and/or          |
| privileged material.  Any review, retransmission, dissemination or    |
| other use of, or taking of any action in reliance upon, this          |
| information by persons or entities other than the intended recipient  |
| is prohibited. If you received this in error, please contact the      |
| sender and delete the material from any computer.                     |
+-----------------------------------------------------------------------+

On Thu, 16 Aug 2001, Tobie Horswill wrote:

{Quote hidden}

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2001\08\17@171758 by Programmer One

picon face
I am not sure about this, but does the os2 out have a 1/4th frequency?

Best regards,
Giles



>I put the resonator on one device and then the OSC2 (out) to the first
>deivce OSC1 (in) and it's OSC2 (out) to the second device OSC1(in).... and
>so on. This worked for me.
>HTH


_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2001\08\20@132811 by Douglas Butler

flavicon
face
Only in RC mode is OS2 at 1/4 frequency.  In the other modes it is at
the same frequency.

Sherpa Doug

> {Original Message removed}

More... (looser matching)
- Last day of these posts
- In 2001 , 2002 only
- Today
- New search...