89C51ED2
in [Design]
|
From: TT_Man on 3 Sep 2008 18:04 ">> Is this an Atmel part? >> If so, I would check the datasheets for updates. >> I know on their 8252/3 series, they made a change to the crystal cap >> requirements. >> Went from 30pf to around 5pf. Would occasionally cause improper >> startup/reset, and very slow operation if it did reset. If they >> changed the oscillator on ED2, that could very well be the problem. >> (?) >> > > Hopefully not without changing the rev level and informing their > customers? Yikes, I sure hope not. > > -- > Regards, Joerg Joerg, I get regular updates on all atmel processor revision changes/data sheet spec changes, . In this respect, Atmel are 100% on the ball. AFAIK there have been none for this particular part......
From: Joerg on 3 Sep 2008 19:14 TT_Man wrote: > ">> Is this an Atmel part? >>> If so, I would check the datasheets for updates. >>> I know on their 8252/3 series, they made a change to the crystal cap >>> requirements. >>> Went from 30pf to around 5pf. Would occasionally cause improper >>> startup/reset, and very slow operation if it did reset. If they >>> changed the oscillator on ED2, that could very well be the problem. >>> (?) >>> >> Hopefully not without changing the rev level and informing their >> customers? Yikes, I sure hope not. >> >> -- >> Regards, Joerg > > Joerg, I get regular updates on all atmel processor revision changes/data > sheet spec changes, . In this respect, Atmel are 100% on the ball. > AFAIK there have been none for this particular part...... > That's good. I'd call them anyhow though. I once had an issue with them regarding an 89C51 that was advertized at a higher clock than it could do. IIRC it was touted as 16MHz but I could only get it to run at 12MHz. They did apologize and other than that it ran in that same design forever. In fact, it's still in production, over a decade now. That's the beauty of 8051 designs, those things are like the VW Beetle. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Eeyore on 3 Sep 2008 21:56 TT_Man wrote: > Anyone using this part experiencing problems? we have used them for 4 years > or so. Date codes up to 0705 work ok, 0814 misbehaves....same chip, same > software, 0814 doesn't execute properly... Have you contacted the manufacturer ? Graham
From: Eeyore on 3 Sep 2008 22:11 Joerg wrote: > TT_Man wrote: > > Anyone using this part experiencing problems? we have used them for 4 years > > or so. Date codes up to 0705 work ok, 0814 misbehaves....same chip, same > > software, 0814 doesn't execute properly... > > Did you check the POR situation? Maybe issue a nice long POR and see if > it'll run? > > The POR circuit on most 8051 is %^&#!! <tantrum censored> so I always > rolled my own. As for BOR, I think many uC designers don't know what > that means ... I think Atmel actually do an app note on that. Graham
From: Eeyore on 3 Sep 2008 22:30
mpm wrote: > On Sep 3, 1:13�pm, "TT_Man" <Some...(a)ntlworld.com> wrote: > > Anyone using this part experiencing problems? we have used them for 4 years > > or so. Date codes up to 0705 work ok, 0814 misbehaves....same chip, same > > software, 0814 doesn't execute properly... > > Is this an Atmel part? > If so, I would check the datasheets for updates. > I know on their 8252/3 series, they made a change to the crystal cap > requirements. > Went from 30pf to around 5pf. Would occasionally cause improper > startup/reset, and very slow operation if it did reset. If they > changed the oscillator on ED2, that could very well be the problem. They'd be nuts to do that though ! Graham |