Yahoo Groups archive

AVR-Chat

Index last updated: 2026-04-28 22:41 UTC

Thread

Re: [AVR-Chat] Unable to download code in ATmega88

Re: [AVR-Chat] Unable to download code in ATmega88

2006-04-04 by John Samperi

At 02:13 PM 4/04/2006, you wrote:
>My crystal clock frequency is 20Mhz .. but the maximum attainable 
>ISP frequency is 1.845 Mhz.

Sorry I see the xtal frequency now... :-)

That's ok because the ISP frequency is only for programming.
REMEMBER however that new chips come with the 1MHz internal
oscillator on so keeping the ISP frequency at about 250KHz
will ensure that new chips will program without having to reset
the ISP frequency every time. If you have chips already preset
for external oscillator at a higher frequency you can set the
ISP frequency higher, I usually don't bother as all of my code is
presently less than 8K so it doesn't take long to program.

>I have 1 more doubt .. In the AVR studio, i've set the clock frequency
>as 20000000 hz in the "Configurations Options"

Hmmm don't know, haven't had to set that, I think that is only
for simulation (??).

Unfortunately I don't use the STK500 for programming (I have the AVRISP)
perhaps someone else that uses the tool can help out more. I will have
to dig out and dust it off one of these days I guess but probably won't
happen untill I kill the fuses in some chips and will need to use
parallel programming :-)



Regards

John Samperi

********************************************************
Ampertronics Pty. Ltd.
11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
Website  http://www.ampertronics.com.au
*Electronic Design * Custom Products * Contract Assembly
********************************************************

Re: [AVR-Chat] Unable to download code in ATmega88

2006-04-04 by Kishore Diggavi

Hi,
Thanks John & David for ur response ..
can u kindly suggest me the lock bits & fuse settings .. i've placed a 20 Mhz crystal on the STK500 board.
My VCC is within tolerence .. I think david is probably right .. may be the serial programming is disabled .. but i hav doubt .. as far as the fuse setting of serial programming @ ATmega88 is concerned, its is not programmable .. i mean u cant select it .. is there any other setting through which serial programming can be disabled??
Kindly throw some light on how much should i select the STK 500 frequency?
As suggested by both of u i will select ISP frequency as 250khz in my future applications.
Once again thank u guys for ur suggestions.
Regards,
Krish.

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.