Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Atmel/AT91SAM9M11/AC97C/COSR#0x0
Codec Status Register
Channel Transmit Ready
Channel Transmit Empty
Transmit Underrun
Channel Receive Ready
Receive Overrun
https://github.com/cmsis-svd/cmsis-svd-data