Overclocking 18F PICs

[Nikki]

Hi,

I'm considering overclocking a PIC18F452. In my search for information on the reliability issues of doing this I came across a web page that has a guy, Karl Boe, overclocking an 18F to 60 Mhz.

<a href="http://www.portlandrobotics.org/meetings/minutes/2002/september.html" TARGET="_blank">http://www.portlandrobotics.org/meetings/minutes/2002/september.html</a>

I've also heard a rumour that 18F PICs are tested to 60 Mhz.

I did a quick test and used a 12.288 Mhz crystal with H4 settings to overclock to 49.152 Mhz. I'm not sure of the long term issues, but the PIC showed no initial problems.

Anyone have opinions on this subject?

Regards,

Nikki
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This message was ported from CCS's old forum
Original Post ID: 13876

[PCM programmer]

:=Hi,
:=
:=I'm considering overclocking a PIC18F452. In my search for information on the reliability issues of doing this I came across a web page that has a guy, Karl Boe, overclocking an 18F to 60 Mhz.
--------------------------------

There's a thread on this in the archives.
<a href="http://www.pic-c.com/forum/general/posts/11142.html" TARGET="_blank">http://www.pic-c.com/forum/general/posts/11142.html</a>

(I would never ship an over-clocked board to a customer --
strictly home use).
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This message was ported from CCS's old forum
Original Post ID: 13885

[Hans Wedemeyer]

Well as I said in the previous thread at 60MHz the UART Baud rate went screwy. I did not have a 12.5 mHz Cyrstal but think it will be OK..

I agree with PCP not to ship an over clocked project. However if the client is made aware of the fact and agree to accept it, then of course I is no problems with it.

I'm looking forward to the day when PIC's will run at 1GHz ....
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This message was ported from CCS's old forum
Original Post ID: 13892

[Nikki]

<font face="Courier New" size=-1>:=Well as I said in the previous thread at 60MHz the UART Baud rate went screwy. I did not have a 12.5 mHz Cyrstal but think it will be OK..
:=
:=I agree with PCP not to ship an over clocked project. However if the client is made aware of the fact and agree to accept it, then of course I is no problems with it.
:=
:=I'm looking forward to the day when PIC's will run at 1GHz ....

What sorts of reliability tests are recommended? I'm only wanting to overclock with a 12.288 MHz crystal

I think you'll probably see a PIC running inside a CPLD at 1GHz far sooner than you think!

Nikki</font>
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This message was ported from CCS's old forum
Original Post ID: 13893

[Hans Wedemeyer]

Best to write a test program to test the featires you are interested in, and then cycle it at expected Min/Max temperatures for some time. If Power can ever fall below 5V ( or what ever you are using) then make sure it runs at that V and a little less at all temperatures.
The whole process takes time and effort, but if you need the higher speed and can't afford to have a failure, it's the only way to ensure wom kind of reliablity.

I ran the PIC16C66 at 33mHz which is over 50\% higher than max and it runs just fine.

Of course if it's a hobby project and you are not upset if the PIC fails, then just do it and watch what happens.
Good luck !
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This message was ported from CCS's old forum
Original Post ID: 13896

[Tomi]

:=I think you'll probably see a PIC running inside a CPLD at 1GHz far sooner than you think!

I don't want to re-construct my PCBs to make place for that big heat-sink and fan
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This message was ported from CCS's old forum
Original Post ID: 13898

[Nikki]

<font face="Courier New" size=-1>Wow! Somehow magically, the subject title changed to one that was cached in IE months ago?! Bad IE, bad!

I apologise.

Nikki</font>
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This message was ported from CCS's old forum
Original Post ID: 13910

[Nikki]

:=:=I think you'll probably see a PIC running inside a CPLD at 1GHz far sooner than you think!
:=
:=I don't want to re-construct my PCBs to make place for that big heat-sink and fan <img src="http://www.ccsinfo.com/pix/forum/smile.gif" border="0">

Awww, what, not even with those nice fancy blue leds? My PC used to have enough fan power to levitate until I installed some flower power heatsinks. :-)

Regards,

Nikki
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This message was ported from CCS's old forum
Original Post ID: 13912