34.6.10 Synchronization
Due to the asynchronicity between the main clock domain (CLK_CAN_AHB) and the peripheral clock domain (GCLK_CAN) some registers are synchronized when written. When a write-synchronized register is written, the read back value will not be updated until the register has completed synchronization.
The following bits and registers are write-synchronized: The lNIT Initialization bit in the CC Control register (CCCR.INIT).