While playing around with SPI, I observed something I found no explanation for:
When setting up the controller (a mega128 in this case, a smaller one wasn´t at hand :) ), all output pins are configured to be LOW. This applies to the SPI pins, too. Then I set up the SPI configuration (clock speed, flag, byte order, etc.). As soon as the SPI is enabled, the MOSI line goes HIGH. Communicating over SPI does work, though.
Is this an intended behavior? The datasheet doesn´t say anything about SPI idle levels (except for the SPI clock, but that is set up properly and does work). Is there some reference to this in another documentation?