[33] DPPI: Non-secure code can detect secure events

This anomaly applies to IC Rev. Engineering A, build codes SICA-BAA.

Symptoms

Non-secure code is able to detect that a secure event has been published to a secure DPPI channel.

Conditions

In a non-secure DPPI channel group, SUBSCRIBE_CHG[n].EN or SUBSCRIBE_CHG[n].DIS is setup to be connected to a secure DPPI channel.

Consequences

Non-secure code can detect that a secure event has been published to a secure DPPI channel. The non-secure code cannot detect which event has been published.

Workaround

Perform one of the following:
  • Avoid using DPPI in secure mode.
  • Configure all channel groups (CHG[n]) to include at least one DPPI channel that is configured as secure. This makes the channel groups secure and blocks them from being used on the non-secure side.
    Note: The non-secure domain can still use the DPPI tasks and events system, but it does not have any available channel groups.
Parent topic: New and inherited anomalies