Post by thread:Over-clocking

Hello everybody! I would like to know what would be the expected behaviour of an over-clocked PIC. In my case I want to use a PIC16F84-04 at frecuencies above the 4Mhz. I've seen projects using 10Mhz xtal and even 12Mhz xtal (pong) with this particular chip. What's the highest frecuency this micro can tolerate? Also, given the fact Microchip produces PIC16F84s for 10Mhz xtals. Is it possible to overclock this ones even higher? I'm asking this because a faster chip would make my project coding easier and the PCB is designed for a 16F84. I'm sure more than a couple of you have this issue xtal clear! (-; Thanks! ------------------------------------ netQ <spam_OUTnetquakeTakeThisOuTinnocent.com> http://virtuaweb.com/picprog "Home of amateur PIC programmers..." -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.2 mQCNAzV38BkAAAEEALfWv9j3f+tZ+z2IW+2o9Ebx4bUGnHjHPqIe0a6yVKawaeV/ Y4I6L2/A0ddbVMG8+qJ0MvHNkr3DzYkpW+hTl9zAzXkKBdZ3GA5bbvot7entl/O2 YDtRWUV730koxBo5iFFUbJH5kbmkox+h3znj34zPnZNWzNaqOAwol3wABfBNAAUT tBxOZXRRIDxuZXRxdWFrZUBpbm5vY2VudC5jb20+ =0bVU -----END PGP PUBLIC KEY BLOCK-----

netQ wrote: > > Hello everybody! > > I would like to know what would be the expected > behaviour of an over-clocked PIC. In my case I want to > use a PIC16F84-04 at frecuencies above the 4Mhz. I've > seen projects using 10Mhz xtal and even 12Mhz xtal (pong) > with this particular chip. What's the highest frecuency > this micro can tolerate? > Also, given the fact Microchip produces PIC16F84s for > 10Mhz xtals. Is it possible to overclock this ones even > higher? > I'm asking this because a faster chip would make my > project coding easier and the PCB is designed for a > 16F84. Most 84s can be speed up to 8Mhz, but note that this doesn't comply with manufacturers specs. Tin canned, 4 legged TTL Oscillators may speed it along at 12Mhz too, but watch out for internal EEPROM read/write cycles! Gary Barnes of Western Australia put me onto the 12Mhz Oscillator trick. Other users have told me that you can get some 4Mhz PICs running at 16 and 20Mhz by just putting a 10Meg resistor across the faster crystal. Don McKenzie .....donKILLspam@spam@dontronics.com http://www.dontronics.com Don's Download Dungeon: http://www.dontronics.com/download.html Australian Electronics Ring http://www.dontronics.com/aering.html Win $500USD Cash. Micro design contest: http://www.simmstick.com

> I would like to know what would be the expected > behaviour of an over-clocked PIC. In my case I want to > use a PIC16F84-04 at frecuencies above the 4Mhz. I've > seen projects using 10Mhz xtal and even 12Mhz xtal (pong) > with this particular chip. What's the highest frecuency > this micro can tolerate? If you're making a hobby project for yourself, go ahead. It either works, or it dosen't. If you're thinking about making more than one, then 4.000 is as fast as I'd go.

> Over clocking doesn't mean it is not going to work > it simply means there is no guaranty will work on > > 1. high or low temperature > 2. noise > 3. vibration > 4. pressure > 5. VDD min and max 6. the next chip out of the tube. 7. all instructions It's just not a good idea.

yea well they say overclocking your computer isnt good either but Ive had a PII 266 running at 412mhz and a PII 333 running at 464 for about a year now.... =] {Quote hidden}> > Over clocking doesn't mean it is not going to work > > it simply means there is no guaranty will work on > > > > 1. high or low temperature > > 2. noise > > 3. vibration > > 4. pressure > > 5. VDD min and max > > 6. the next chip out of the tube. > 7. all instructions > > It's just not a good idea. >

Here in Argentina, our one and only local Microchip provider does not import 10Mhz 16F84 parts, they just sell 4Mhz ones. The say that all 4Mhz parts works perfectly at 10Mhz, so there is no need for them to import the fast parts... {Quote hidden}> > Over clocking doesn't mean it is not going to work > > it simply means there is no guaranty will work on > > > > 1. high or low temperature > > 2. noise > > 3. vibration > > 4. pressure > > 5. VDD min and max > > 6. the next chip out of the tube. > 7. all instructions > > It's just not a good idea. >

part 0 478 bytes content-type:text/x-vcard; charset=us-ascii; name="vcard.vcf" (decoded 7bit) Pailoor Andres Tarzia wrote: > The say that all 4Mhz parts works perfectly at 10Mhz, so there is no need for > them to import the fast > parts... > Content-Type: text/x-vcard; charset=us-ascii; name="vcard.vcf" Content-Description: Card for Ravi Pailoor Content-Disposition: attachment; filename="vcard.vcf" Content-Transfer-Encoding: 7bit Attachment converted: wonderland:vcard.vcf (TEXT/CSOm) (0002F4D2)

> Here in Argentina, our one and only local Microchip provider > does not import > 10Mhz 16F84 parts, they just sell 4Mhz ones. The say that all > 4Mhz parts > works perfectly at 10Mhz, so there is no need for them to > import the fast > parts... I do think that 04 parts have failed the 10 test Regards Benjamin Petersen

> >> Here in Argentina, our one and only local Microchip provider >> does not import >> 10Mhz 16F84 parts, they just sell 4Mhz ones. The say that all >> 4Mhz parts >> works perfectly at 10Mhz, so there is no need for them to >> import the fast >> parts... > >I do think that 04 parts have failed the 10 test > >Regards >Benjamin Petersen I didn't test them at 10Mhz