Yes, yes, I know that it must be between 1 and 4 clock cycles of a target device. But... We don't know it if clock is provided by internal rc generator or external quartz. So is there any possible way to find the fastest allowed spi frequency?
And one more question. I've read that we can provide external clock source when programming. But how can we tell to AVR about this? I thought that it always uses internal rc generator when being programmed.
