1 Reply Latest reply on Jan 23, 2019 3:29 AM by himam_31

    USB and SleepTimer

    RiMo_301056

      Hi,

      in a battery powered PSoC3 design I use the USB Full Speed component. This in turn requires that I set the ILO timer to 100kHz.

      Even though the reason for this is not 100% clear to me, another forum post sheds some light, stating that:

      The ILO must be set to 100 kHz for USB bus reset interrupt to function correctly.

      Then, CTW can not be the wakeupSource for the Sleep mode,but FTW.

       

      On the other hand, when no USB cable is attached, I would like to let my device sleep for long intervals (ideally 1 second or more). The "SleepTimer" component comes handy for this. But its datasheet declares that it uses the ILO timer's 1kHz output.

       

      Now I understand that the ILO timer has only one wired output, therefore above two ILO requirements (one for 100kHz and one for 1kHz) seem to be in conflict.

       

      Here are my questions:

      1. Is this really the case, or can the USB and SleepTimer components work along on the same device (the "Clocks" configuration panel in PSoC Creator indeed allows to enable both the 1kHz and the 100kHz ILO clocks, see attached screenshot. What does that mean)?
      2. Can the SleepTimer work on a 100kHz ILO timer clock? (obviously, that would shorten the sleep intervals by a factor of 100)
      3. What other wakeup sources would be recommended to obtain long sleep intervals (in the order of 1 second) without considerably increasing the current consumption during sleep?

       

      Thanks for any advice.

        • 1. Re: USB and SleepTimer
          himam_31

          Hello,

           

          1. Is this really the case, or can the USB and SleepTimer components work along on the same device (the "Clocks" configuration panel in PSoC Creator indeed allows to enable both the 1kHz and the 100kHz ILO clocks, see attached screenshot. What does that mean)?

                1 kHz and 100 kHz clocks can run independently, are not synchronized to each other, and can be enabled or disabled together or independently.

           

          2.Can the SleepTimer work on a 100kHz ILO timer clock? (obviously, that would shorten the sleep intervals by a factor of 100)

            Sleeptimer can work only with the 1KHz ILO.

           

          3. What other wakeup sources would be recommended to obtain long sleep intervals (in the order of 1 second) without considerably increasing the current consumption during sleep?

          Do you need a periodic wake up?

           

          Since the 1KHz ILO is enabled by default you will be able to use it for the SleepTimer. Are you facing any specific issues with Sleeptimer on the USB projects?

           

          Thanks,

          Hima