Module regs
- Btr
 - bit timing register
 - Esr
 - interrupt enable register
 - Fa1r
 - filter activation register
 - Ffa1r
 - filter FIFO assignment register
 - Fm1r
 - filter mode register
 - Fmr
 - filter master register
 - Fr1
 - Filter bank 0 register 1
 - Fr2
 - Filter bank 0 register 2
 - Fs1r
 - filter scale register
 - Ier
 - interrupt enable register
 - Mcr
 - master control register
 - Msr
 - master status register
 - Rdhr
 - receive FIFO mailbox data high register
 - Rdlr
 - mailbox data high register
 - Rdtr
 - mailbox data high register
 - Rfr
 - receive FIFO 0 register
 - Rir
 - receive FIFO mailbox identifier register
 - Tdhr
 - mailbox data high register
 - Tdlr
 - mailbox data low register
 - Tdtr
 - mailbox data length control and time stamp register
 - Tir
 - TX mailbox identifier register
 - Tsr
 - transmit status register