Module regs
- Cr1
 - Control register 1
 - Cr2
 - Control register 2
 - Icr
 - Interrupt clear register
 - Isr
 - Interrupt and Status register
 - Oar1
 - Own address register 1
 - Oar2
 - Own address register 2
 - Pecr
 - PEC register
 - Rxdr
 - Receive data register
 - Timeoutr
 - Timeout register
 - Timingr
 - Timing register
 - Txdr
 - Transmit data register