66.4.2 Power Management
The MCAN can be clocked through the Power Management Controller (PMC), thus the programmer must first configure the PMC to enable the MCAN clock.
In order to achieve a stable function of the MCAN, the system bus clock must always be faster than or equal to the CAN clock.
It is recommended to use the CAN clock at frequencies of 20, 40 or 80 MHz. GCLK allows the system bus and processor clock to be modified without affecting the bit rate communication.