how to deal with ACK and DATA one after the other in I2C efr32fg14

in I2C We have the IF register to catch the ACK from the slave ,
And we have I2C0->RXDATA to catch the recieved data .
But as shown in the diagram bellow i cant code
Pseudo code:
check if ACK was recieved
wait a little and catch the input data with I2C0->RXDATA.

what is the method of handling two types of data intended for different registers coming one after the other?

Thanks.