2 Replies Latest reply on Nov 18, 2019 6:21 PM by YuMa_1534086

    Regarding RawCount spike noise at CapSense Tuner(Asynchronized mode)


      Hello Cypress.


      I sometimes see RawCount spike noise(about 250 counts) like attached PNG file at CapSense Tuner(Asynchronized mode).

      Such spike noise does not occur in Synchronized mode.




      Spike noise seems to be occurred due to read RawCount(2byte) during updating(RawCount update is not complete).

      For example, spike noise occurs when reading RawCount data at below timing.


      RawCount MSB was updated, but LSB was not updated yet(LSB is previous data)


      RawCount LSB was updated, but MSB was not updated yet(MSB is previous data)



      Is my understanding correct?

      Attached file is log file of CapSense Tuner.






      If Q1 is yes, which will be updated first, MSB or LSB of CapSense data?

      Is LSB updated first because Cortex M0 uses little-endian format?(LSB -> MSB?)

      Or MSB first?(MSB -> LSB?)



      Best Regards.

      Yutaka Matsubara