.. _bgpr_retention: BGPR Retention ====================== Overview -------- This example project demonstrates the data retention function of the BGPR register. Board Setting ------------- Ensure that the VBAT pin is powered, for example, greater than 3V. HPM6800EVK has a known issue about VBAT, please refer to :ref:`Board known issue details ` Running the example ------------------- - When the Retention field of BPOR is initialized and set, the serial terminal will output the following information and the LED will not light up. .. code-block:: console bgpr retention example bgpr retention enable and data initialized, please keep vbat and power down! Or .. code-block:: console bgpr retention example bgpr data retention failure, index: 0! bgpr data retention failure, index: 1! bgpr data retention failure, index: 2! bgpr data retention failure, index: 3! bgpr data retention failure, index: 4! bgpr data retention failure, index: 5! bgpr data retention failure, index: 6! bgpr data retention failure, index: 7! Because bgpr data compare failure, so re-initialize bgpr data, please keep vbat and power down again! - After power off/on again or press reset. The serial port terminal will output the data retention function verification result. For example, when the verification is successful, the output log is as follows: .. code-block:: console bgpr retention example bgpr data retention success! - In addition, the status of the LED light can also indicate the verification result of the data retention function. If the verification is successful, the LED will light up; Otherwise, it will not light up.