While Loop or setWatch?

I am interfacing Azoteq IQS263 Capacitive Touch sensor (Datasheet) with Espruino. The sensor is I2C interface with RDY line.

As per the datasheet the device will response when RDY pin goes low. So I will have to wait and monitor when the RDY pin goes low to start and communication. Well in active this pin is bi-directional and communication windows opens when it is LOW and resumes sensing/calculating when it is HIGH.

What should be the approach for this?
1- While loop??

 while(rdyPin.read()){ //wait for the IQS to change from ready to not ready
  }

OR

setWatch(watchFun, rdyPin, {repeat: true, edge: 'falling' });