Module regs

Structs

• Cr1
  control register 1
• Cr2
  control register 2
• Crcpr
  CRC polynomial register
• Dr
  data register
• I2scfgr
  I2S configuration register
• I2spr
  I2S prescaler register
• Rxcrcr
  RX CRC register
• Sr
  status register
• Txcrcr
  TX CRC register