Checkout section 22.4.5.4 "Protocol Timing" of the MPC5566 Reference Manual.
The relevant parameters are set in the CAN Control Register (CAN_CR), described in section 22.3.3.2.
As an example:
To get a bit rate of 1MHz, choose:
CLK_SRC = 0 (crystal source)
PRESDIV = 0
This will set the time quanta frequency, ftq, to 8 MHz
Then, choose a combination of PROPSEG, PSEG1 and PSEG2 to give 8 'time quanta' per bit time
Bit rate will then be
ftq / num time quanta = 8 Mhz / 8 = 1Mhz, as desired
