Post by thread:16C84 @ 11.0592MHz

Hi, Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. I know it is 1.0592Mhz faster than the rating, but what I'm thinking about is sharing the clock on a circuit which already has an Atmel 89C2051 running @ 11.0592MHz with a '84. I could divide the clock, but what I'd like is to run the '84 as fast as possible. Alternatley if someone has a suggestion of how to slow the clock for the PIC. Regards.Elvin

At 11:23 PM 3/25/97, Elvin Slavik wrote: >Hi, >Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. >I know it is 1.0592Mhz faster than the rating, but what I'm thinking >about is sharing the clock on a circuit which already has an Atmel >89C2051 running @ 11.0592MHz with a '84. Personally,I haven't tried anything like that. I heared that most of the 16C84 rated at 4MHz will work fine at 10MHz too, that seems reassuring. If you are talking about the design of a few circuits: go ahead, it will work fine in 99% of the cases. If you are talking about mass production (I assume: not the case), that's another cup of tea. 1% dropout on each of the 100 components of a device means that less than 1% of the devices will work... Dirk Van den Berge spam_OUTdvdbTakeThisOuTvub.vub.ac.be AZ VUB Radiotherapy Dep't Laarbeeklaan 101 B-1090 Brussels Belgium Fax: ++32-2-477 62 12 Tel: ++32-2-477 60 41

At 11:23 PM 3/25/97, Elvin Slavik wrote: >Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. >I know it is 1.0592Mhz faster than the rating, but what I'm thinking >about is sharing the clock on a circuit which already has an Atmel >89C2051 running @ 11.0592MHz with a '84. I believe they are rated to 10 MHz; I use them for PROTOTYPING ONLY at speeds up to 16 MHz; 20 MHz will not work; 18 MHz on a good day, certainly not reliable. Is this design for production? If no, then go ahead and use the 11 MHz signal. If it will be in production in any quantity, you will absolutely want to speak with someone at MCHIP. Do you need the EEPROM, or could you switch over to a less-expensive variant, such as the 16C61-20 or such, that is rated at 20 MHz? Also, will your supply voltage stay a constant, good +5V? How about temp range? I believe these somewhat affect what freq. range is likely to work. Anyone know if MCHIP plans a 20 MHz '84? That would be ideal for quick prototyping fast circuits. -Todd .--------------------------------------------------------------. / .-. E-Lab Digital Engineering, Inc. .-. \ | / \ Embedded Control & Integrated Circuit Solutions / \ | | \_. | | / | |\ | /| http://www.netins.net/showcase/elab |\ | /| | `---' | | `---' | | |Inquire about our EDE700 Serial LCD Screen Driver!| | | | (712) 944-5344 FAX:(712) 944-5501 | | | |--------------------------------------------------| | \ / \_____/ `---'

On Tue, 25 Mar 1997, Elvin Slavik wrote: > Hi, > Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. > I know it is 1.0592Mhz faster than the rating, but what I'm thinking > about is sharing the clock on a circuit which already has an Atmel > 89C2051 running @ 11.0592MHz with a '84. I could divide the clock, > but what I'd like is to run the '84 as fast as possible. > Alternatley if someone has a suggestion of how to slow the clock > for the PIC. > > Regards.Elvin > i'd just like to use this occassion to say that I can run my 4MHz pic at 16Mhz. Thats pretty good. Its a 16C84 and i could write /read the eeprom, do interrupts and everything as normal. I basically ran a 4mhz program at 16Mhz. its definitely a 4mhz cos it says -04P on the package. Didn't work at 25Mhz :(

At 02:21 PM 3/25/97 -0600, you wrote: {Quote hidden}>At 11:23 PM 3/25/97, Elvin Slavik wrote: > >>Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. >>I know it is 1.0592Mhz faster than the rating, but what I'm thinking >>about is sharing the clock on a circuit which already has an Atmel >>89C2051 running @ 11.0592MHz with a '84. > >I believe they are rated to 10 MHz; I use them for PROTOTYPING ONLY at >speeds up to 16 MHz; 20 MHz will not work; 18 MHz on a good day, certainly >not reliable. Is this design for production? If no, then go ahead and use >the 11 MHz signal. If it will be in production in any quantity, you will >absolutely want to speak with someone at MCHIP. Do you need the EEPROM, or >could you switch over to a less-expensive variant, such as the 16C61-20 or >such, that is rated at 20 MHz? Also, will your supply voltage stay a >constant, good +5V? How about temp range? I believe these somewhat affect >what freq. range is likely to work. Anyone know if MCHIP plans a 20 MHz >'84? That would be ideal for quick prototyping fast circuits. > > -Todd > > > > > .--------------------------------------------------------------. > / .-. E-Lab Digital Engineering, Inc. .-. \ > | / \ Embedded Control & Integrated Circuit Solutions / \ | > | \_. | | / | > |\ | /| http://www.netins.net/showcase/elab |\ | /| > | `---' | | `---' | > | |Inquire about our EDE700 Serial LCD Screen Driver!| | > | | (712) 944-5344 FAX:(712) 944-5501 | | > | |--------------------------------------------------| | > \ / \_____/ > `---' > > Why not just use the 16F84 it is rated at 10 mhz. dragon .....dragonKILLspam@spam@topher.net

Thanks to all giving advice on running PIC *overspeed* @ 11.0592MHz. For those interested, what I'm thinking of doing is seting up the PIC as a programmable oscillator to drive an IR diode for remote control. By going to 10+ MHz, a tight loop (i.e. pin on, nop, pin off, jump) oscillates at 500Khz, inserting delays will allow it to be *tuned* to other frequencies such as standard remote control @ 38KHz. An external interrupt on B0 would be used to receive serial data to transmit. It would be nice to also have a variable frequency receiver, but I think this is maybe a bit too hard. The choice for using a PIC rather than a simple 555 based circuit is space (ie 1 chip+res+diode) and the other is software control. Regards.Elvin

In message <Pine.GSO.3.95.970326085620.25485A-100000@acacia>, "dlionsKILLspamacs.itd.uts.edu.au" <.....dlionsKILLspam.....ACS.ITD.UTS.EDU.AU> writes >On Tue, 25 Mar 1997, Elvin Slavik wrote: > >> Hi, >> Has anyone any comments/experience on running a 16C84 @ 11.0592MHz. >> I know it is 1.0592Mhz faster than the rating, but what I'm thinking >> about is sharing the clock on a circuit which already has an Atmel >> 89C2051 running @ 11.0592MHz with a '84. I could divide the clock, >> but what I'd like is to run the '84 as fast as possible. >> Alternatley if someone has a suggestion of how to slow the clock >> for the PIC. >> >> Regards.Elvin >> > > i'd just like to use this occassion to say that I can >run my 4MHz pic at 16Mhz. Thats pretty good. Its a 16C84 and i could >write /read the eeprom, do interrupts and everything as normal. I >basically ran a 4mhz program at 16Mhz. its definitely a 4mhz cos it says >-04P on the package. Didn't work at 25Mhz :( A colleague of mine is doing the same - for a project at home, not work. Leon -- Leon Heller Amateur radio callsign: G1HSM Email: EraseMEleonspam_OUTTakeThisOuTlfheller.demon.co.uk http://www.lfheller.demon.co.uk Tel: +44 (0) 118 947 1424 (home) +44 (0) 1344 385556 (work)