AN4759

STM32L5 API and internal tamper detection application example

9STM32L5 API and internal tamper detection application example

9.1X-CUBE-RTC for internal tamper detection application

X-CUBE-RTC shows an implementation of the internal tamper detection in the folder:

STM32CubeExpansion_AN4759_RTC_STM32L_Vx.y.z\Projects\NUCLEO-L552ZE Q \RTC_InternalTamperCalOvf

This example uses the RTC firmware driver API mentioned in Section 6 and Section 7 . It is developed for the NUCLEO-L552ZE-Q board and exploits the ITAMP5 signal associated to a RTC calendar overflow event.

The user must supply the Nucleo board via USB, then compile and run the firmware with the preferred IDE. For IAR Embedded Workbench, open the RTC_Synchronization.eww file. For MDK-ARM, open the RTC_Synchr onization.uvprojx file. For STM32CubeIDE, open the .cproject file.

The X-CUBE-RTC simply configures the RTC calendar at 23:59:30 on the 31st of December of the year xx99 and activates the internal tamper 5. The user can choose the polling mode or interrupt mode with the ITAMP_INTERRUPT constant in main.h: 1 is interrupt mode, 0 is polling mode.

When the seconds pass 59, the internal tamper event occurs and the green user led 1 PC7 if in polling mode, or the blue user LED2 PB7 if in interrupt mode, is turned on.

RTC_DR and RTC_TR allow the contents of the RTC calendar to be observed in debug mode. The user can easily modify this example to exploit all the others internal tamper event sources.