AN4759

RTC3 secure and privileged protection modes

2.15RTC3 secure and privileged protection modes

Some STM32 MCUs can run in secure or non-secure mode. Each mode having its own environment, allowing a trustful zone, not accessible in non-secure mode, to be maintained in secure mode ( TrustZone feature).

A second level of restriction and security is available with part of each environment associated to a privileged or unprivileged mode.

On some products (see Table 4 and Table 5), the registers programming allow the user to restrict the read/write operation on RTC/TAMP registers to secure or privileged modes. Some configuration bits establish the restriction only for some RTC registers. These registers/bits to program are product dependent, then not detailed here (refer to the product reference manual).