Hello Shany,
Provided you configure the ISC module for FEE mode, the maximum bus frequency will be 16.777 MHz. Other selectable bus frequencies are the sub-multiples 8.389, 4.194 and 2.097 MHz.
However, if you select FBE mode, the maximum bus frequency will reduce to 16.384 kHz. The SCI module will be virtually unusable. You will not be able to erase or program flash memory from within your code, for non-volatile data. You should still be able to debug via BDM, because the clock source for this module is derived from the DCO within the ICS module
The SPI and IIC module will be very slow, but they should still work. The ADC module should also remain operative by selecting the async. clock generator within the module. The bus clock might be too slow to use the 1kHz oscillator as the COP timer source (insufficient instructions executed within the timeout period), but the bus clock can still be used, to give an extended timeout period.
Of course, if FEE mode is continuously present, there will be none of these issues.
Regards,
Mac
