STM32H5 I3C SDR READ issue

wulin · ‎2025-01-16

Hello, when I was using the STM32H563 I3C, I found that when configured with VDDIO2 = 1.2V and a frequency of 12.5MHz, the data read in SDR mode would be misaligned. The waveform received on the SDA line was 0xF9, but the MCU received 0x7C. After I increased the VDDIO voltage to 1.5V, the data read was correct. And I tried VDDIO2=1.2V, frequency =6.25Mhz, data was correct, too.

SofLit · ‎2025-01-17

Hello @wulin and welcome to the community,

It could be something related to the HSLV configuration. Refer to the datasheet / and tables:

Output timing characteristics VDDIO2 1.2 V range (HSLV OFF)

Output timing characteristics VDDIO2 1.2 V (HSLV ON)

Did you activate the HSLV?

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