Cirrus Logic CS4955 - Manual (Page 28)

CS4954 CS4955
28 DS278F6
tions of GPIO_DATA_REG when it detects regis-
ter address 0×0A through the I²C interface. A
detection of address 0×0A can happen in two ways.
The first and most common way this will happen is
when address 0×0A is written to the CS4954/5 via
its I²C interface. The second method for detecting
address 0×0A is implemented by accessing register
address 0×09 through I²C. In I²C host interface op-
eration, the CS4954/5 register address pointer will auto-increment to address 0×0A after an address
0×09 access.
The GPIO port PDAT [7:0] pins are configured for
output operation when the corresponding
GPIO_CTRL_REG [7:0] bits are set. In GPIO out-
put mode, the CS4954/5 will output the data in
GPIO_DATA_REG [7:0] bit locations onto the
corresponding PDAT [7:0] pins when it detects a
register address 0×0A through the I²C interface.