Hello @northh_sven ,
This is a feedback from the expert:
For revision B devices, the workaround described in Errata ES0620 section 2.2.18 is intended to ensure that the reset circuitry is correctly configured before any subsequent assertion of the NRST pin.
The initial software reset is not necessarily required immediately after the first power-on if the application can guarantee that the workaround will be applied before any external NRST event occurs. In practice, the application may:
- Configure SYSCFG_CM55RSTCR.CORE_RESET_TYPE to select the Power-On Reset behavior.
- Detect an upcoming reset request at the application level.
- Execute the final part of the workaround by issuing NVIC_SystemReset() before the external reset is expected.
This software reset updates the internal reset circuitry configuration and ensures that subsequent NRST assertions operate as intended.
If the workaround is not applied before an NRST event occurs, there is a risk that the reset circuitry will be affected by the erratum and the device may not reset correctly. Based on internal observations, the occurrence rate is typically below 10%; however, this figure is provided for information only and is not guaranteed.
At present, there is no supported alternative that completely avoids the software reset requirement on revision B devices. The only definitive solution is to use a device revision in which this erratum has been corrected.
To better assess the impact on your design, could you please clarify the current status of your project (evaluation, development, validation, or production phase)?
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