Module regs
- Brr
- Baud rate register
- Cr1
- Control register 1
- Cr2
- Control register 2
- Cr3
- Control register 3
- Cr2Usart
- Control register 2
- Cr3Usart
- Control register 3
- Dr
- Data register
- Gtpr
- Guard time and prescaler register
- Sr
- Status register
- SrUsart
- Status register