I3C controller SCL line is stall on STM32H563ZI

[RonenW]

Hi,

I am using the STM32H563ZI with the MB1404C board and running the “I3C_Controller_HotJoin_IT” example from the following repository: https://github.com/STMicroelectronics/STM32CubeH5/tree/main/Projects/NUCLEO-H563ZI/Examples/I3C/I3C_Controller_HotJoin_IT.
The target device is a different board, not another STM32H563ZI - for example, the “I3C Protocol Analyzer and Exerciser” from Prodigy Technovations.
After initializing the I3C controller and connecting the I3C target device to the bus, the SCL line of the I3C controller continuously toggles.

Using STM32 Sidekick, I identified the following errata:

Errata: Constant SCL Ticking with I3C Controller on STM32H563ZI

1. Known Issue Description

When using the STM32H563ZI in I3C controller mode (such as with the I3C_Controller_HotJoin_IT example), there is a documented errata where, after initialization, the controller may incorrectly detect the SDA line as low, interpret it as a start request, and activate the SCL clock. This results in the controller generating a 0x7F address with RNW bit = 1, which is not acknowledged, causing unexpected bus activity including constant SCL ticking. This errata affects STM32H503CB/EB/KB/RB and STM32H523xx/33xx devices.