Dear Dialog Semi,
we use nRESET, nIRQ on VDD_IO1 with 1.8V to drive a CPU input. The signals are configured for open drain operation with a pull up to 3.3V (CPU side). From the datasheet, table 4.4 I read that the maximum allowed voltage in open drain mode is VDDREF. In our case this is 5V (Vsys).
Can you confirm the 3.3V pull up is within specification for the two signals.