Question: How do you stop and start the FX3 oscillator during device Suspend and Resume?
There is no explicit API provided in the FX3 SDK to stop/start the oscillator. However, the CyU3PSysEnterSuspendMode() API puts the device in a low-power suspended mode and stops the FX3 oscillator.
Ideally, this API should be called on receiving the Suspend event from the host on the USB bus. This API does not return until the device is woken up again from one of three wakeup sources (USB wakeup, P-Port wakeup, and UART wakeup). When one of these wakeup sources is triggered, the oscillator is started again, the core is put into its active operational mode, and the API returns to the application code.