Overclocked microcontroller and other questions...

[Guest]

Does anybody have any experience with a AT90S2313-10PC (10MHz)... is it possible to use a 12 MHz quartz?
I'm asking because I have this programmer http://futurlec.com/AtmelProg2.shtml and the only chip I can still get is the 2313...
or can I use this programmer also with the newer AVR types?
I used this programmer 6 years ago to program AT89C2051-24PC, but now I need USB to RS485 (IBM Port 5b) to connect an old bar code scanner to my PC.
I still have a AT89C55WD-24PC spare part but I think I can not use this chip because of the internal tact divider, is this true?
What would you do, should I first get a new programmer? Or is there any other solution?

Markus


PS: what is the difference between a -10PC and -10PI??
PPS: Thank you for any help!

[Grendel]

I still have a AT89C55WD-24PC spare part but I think I can not use this chip because of the internal tact divider, is this true?

Depends, usually the internal clocks have more tolerance than the USB spec allows (+/- 1.5% for low speed devices.) Use of a crystal oscilator is strongly recommended.

What would you do, should I first get a new programmer? Or is there any other solution?

Most AVRs are easy to program using the SPI interface. A particular simple method is described here eg.

PS: what is the difference between a -10PC and -10PI??

I stands for Industrial, C for Consumer. The I versions have a bit broader operating ranges (mainly operating temp IIRC.)

[christian]

Does anybody have any experience with a AT90S2313-10PC (10MHz)... is it possible to use a 12 MHz quartz?

I have tried a couple of them and none failed, even at 3.5 V....