Both the FTM and DSPI sections of the K60 reference manual make reference to the "system clock" being the clock source for these peripherals (see below). But "system clock" has a very specific meaning as defined in section 5.4 Clock Definitions. It relates to the core clock.
All indications are these peripherals actually use the "[Peripheral] Bus Clock", which is a maximum 1/2 the core clock. Is this indeed the case?
If so this needs a-fix'n in the Reference Manual.
18.104.22.168 Baud Rate Generator
The Baud Rate is the frequency of the Serial Communication Clock (SCK). The system
clock is divided by a prescaler (PBR) and scaler (BR) to produce SCK with the
The FTM features include:
• FTM source clock is selectable
• Source clock can be the system clock, the fixed frequency clock, or an external