Re: [avr-chat] Cannot connect to STK600 with avrdude

[Joerg Wunsch]

Hayden Muhl <address@hidden> wrote:

> The -B option seems to have solved the problem. I can also reproduce
> the problem by setting SCK back to 1 us. This will let me get my
> work done, and I'll be able to get you the output from AVR Studio at
> some point, too.

If that solved the issue, there's no need to test against AVR Studio
again.  Sorry, I missed the point initially that you were simply
overclocking the ISP clock.

The ISP clock is required to be less than 1/4 of the CPU frequency
(due to internal synchronization effects).  With a default CPU clock
of 1 MHz (+/- RC oscillator tolerance), it must thus be less than
250 kHz.  -B10 makes it 100 kHz only (which is a sane fallback), I
guess -B5 will also work.

If your controller has a sufficiently high supply voltage so you can
run at a higher clock speed, go ahead, and clear the CKDIV8 fuse.
That will make it run at 8 MHz (+/- tolerances), so -B1 should work
again, which will you gain quite some ISP performance boost.

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)