4 Replies Latest reply on Aug 1, 2016 3:04 AM by chai.yang

    SD card affecting RTC

    chai.yang

      I am having a weird issue with a board I designed using the 68-QFN packaged PSoC 5. Whenever I insert the mico SD card into my board, the RTC seems to stop working as in it fails to count or increment. This does not happen using the dev kit however so I am a little confused. For the layout of the PSoC chip, I followed the recommenced layout in the datasheet and am powering it though a 5V regulator. The RTC is using the internal XTAL 32 kHz clock. The micro SD card connector is routed directly to assigned PSoC 5 pins since, I believe, its logic level is 3.3V. Using a logic analyzer, I can see that whenever the SD card was removed, the RTC would count correctly and when the SD card was inserted the RTC would just remain at the time I set it to on startup. Any ideas? (The SD card does read and write correctly by the way)

         

      Thanks