Further inflrmation on this, which seems important is as follows. Application note AN77900 says,
Here is the format of the CyPmSleep()
CyPmSleep(uint8 wakeupTime, uint16 wakeupSource)
CyPmSleep() function has two parameters, wakeupTime and wakeupSource.The wakeupTime parameter is used to set the frequency of a timer and unmask it as a wakeup source. The wakeupSource parameter is used to unmask the asynchronous and component-based wakeup sources.