67.6.20 Security and Safety Analysis and Reports

Several type of checks are performed when a TC channel is enabled.

The peripheral clock of the TC is monitored by a specific circuitry to detect abnormal waveforms on the internal clock net that may affect the behavior of the TDES. Corruption on the triggering edge of the clock or a pulse with a minimum duration may be identified. If the flag TC_SSRx.CGD is set, an abnormal condition occurred on the internal clock net. This flag is not set under normal operating conditions.

The internal counter of a TC channel is also monitored and if an abnormal state is detected, the flag TC_SSRx.SEQE is set. This flag cannot be set under normal operating conditions.

The software accesses to the TC are monitored and if an incorrect access is performed, the flag TC_SSRx.SWE is set. The type of incorrect/abnormal software access is reported in TC_SSRx.SWETYP (see TC_CSRx for details). As an example, when the TC channel is configured in Capture mode, reading TC_RAx when TC_SRx.LDRAS=0 asserts the SWE flags. TC_SSR.ECLASS is an indicator reporting the criticality of the SWETYP report.

The flags CGD, SEQE, SWE, WPVS are automatically cleared when TC_SSRx is read.

If one of these flags is set, the flag TC_SRx.SECE is set and triggers an interrupt if the TC_IMRx.SECE bit is ‘1’. SECE is cleared by reading TC_SRx.