To write a register in the MMD1 extended register set:
- Write the value 0x1 (address function field = 00, DEVAD = '00001') to register REGCR.
- Write the desired register address to register ADDAR.
- Write the value 0x4001 (data, no post increment function field = 01, DEVAD = '00001') to register REGCR.
- Write the content of the desired extended register set to register ADDAR.