Hello Takepiro,
1. Good catch. This is confusing. The SigmaStudio indicates this MP_MODE is an input. I will need to look into this and get back to you on this. It would make sense this MP_MODE = '001' is an output port mode, as this allows an I2C or SPI host control port to use the ADAU145x MPx pins as additional GPIOs for the host MCU.
2. The defaut value of the MPx_WRITE register is '0', which most likely it would be low output until written to with '1'.
-JT