You cannot use this as an ordinary GPIO. However, may use this as a control input pin in the GPIF.
In your GPIF Designer, add an input pin and select the "INT" in the drop down list.
In the state machine, you can have a transition equation as which goes from one state is another when this INT Control pin goes high or low. In the resulting states, you can add the INTR_CPU action. This would trigger an interrupt to the firmware which can be handled by a callback function registered using CyU3PGpifRegisterCallback. Refer the FX3 API GUide and GPIF Designer User guide for details on CyU3PGpifRegisterCallback and INTR_CPU.
- Madhu Sudhan