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    CY8C4248LQI-BL583 :Incorrect baud rate on UART and BLE not functioning

    JiSi_2146306

      Hello,

       

      We are facing strange trouble on the third revision of our boards.

      Below are the observations:

      1. Able to correctly flash CY8C4248LQI-BL583 every time.

      2. I am setting baud rate for UART to 115200 in firmware and in reality, the baud rate is 96318(83% of expected).

      3. Same is the case with I2C Master Clock is also 83% of expected.

      4. I used CyDelay(100). And the actual delay is more than 100ms.

      5. Earlier I suspected trouble with Crystal. I probed XTALO and XTALI. They seem fine with a sine wave of 24Mhz(Attached scope capture).

      6. The device also reset after running for some time(3-4 seconds).

      7. BLE is not at all functional.

      8. Verified voltages on VDDA, VDDD and VDDR. They are stable.

       

      The PCB revision doesn't seem to change much. The circuit is same just minor layout changes in component placement.

      How to debug this issue?

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