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H743xI Datasheet and Reference manual apparent inconsistencies: I2C kernel clock and 20mA capability

LuizLS
Associate II

References: Reference manual RM0433 Rev 5, June 2018 (for STM32H743/753 and STM32H750)

Datasheet DS12110 Rev 5, July 2018 (for STM32H743xI)

I am taking a course on microcontrollers using the Nucleo-H743ZI board and finding a few issues along the way, both with the MCU itself and with the documentation. I would like that someone (from ST would be nice) familiar with this MCU to clarify the disparities described here.

There is no information about these issues in the errata sheet for this device (document ES0392 Rev 6, June 2019).

(1) Datasheet (page 183) says "the 20 mA output drive requirement in Fast-mode Plus is not supported"; Reference manual (table 370, page 1936) says it is.

(2) Reference manual (Section 46.4.2, page 1938) gives formula for I2C kernel clock requirements (maximum period, minimum frequency):

0690X00000As7K1QAJ.jpg

Datasheet (table 101, page 183) has a table with values different from the predicted by that formula. I have compared the formula result (using the t_LOW and t_HIGH values from the I2C specification) with the datasheet table:

0690X00000As7MCQAZ.jpg

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