I've been having problems generating a clock for the 3 wire-mode USI (SPI). The Timer0 is initialized and working. I would like to use Timer/Counter0 overflow option for generating the SCK for SPI. I've set the USICR=0x14 and the clock should then be generated if the Timer/Counter0 is running(?). Both TIMSK and TIFR have been set to 0x00.
Any ideas why I have no SCK?