PSoC® 3 Watchdog Timer Works Only with ILO Set to 1 kHz - KBA212064

Version: **

 

Question:

 Why doesn't the watchdog timer in PSoC 3 work when the ILO is set to 33 kHz or 100 kHz?

 

Answer:

When the ILO is set to 33 kHz or 100 kHz, the 1-kHz oscillator is disabled and therefore the watchdog timer stops functioning properly because it is clocked to the 1-kHz oscillator. To make it work at these clock frequencies, you should start the 1-kHz oscillator along with the 100-kHz oscillator. This can be done in the code by using the CyILO_Start1K() API. Note that the ILO 1-kHz oscillator is always enabled by default, regardless of the selection in Clock Editor. Therefore, this API is only needed if the oscillator was turned off manually.