stm32f334 i2c slave speed

[tri.1]

Stm32f334 i2c works in slave mode , select i2c kernel clock 72mhz.

datasheet says it's i2c fast-mode+ support up to 1mhz, but I found that it can be accessed stably by a master with scl at 2.5mhz. Is it ok to use a master scl speed faster than 1mhz to communicate with the mcu, what's the mcu's i2c scl speed limitation as a slave ?

and how "I2C timing configuration tool " can help to set the timing reg in this situation, now i set the timing reg to 0x0.

[Foued_KH · Accepted solution]

Hello @tri.1​ ,

The maximum frequency for the I2C communication is 1MHz.

"The interface is connected to the I2C bus by a data pin (SDA) and by a clock pin (SCL). It can be connected with a standard (up to 100 kHz), Fast-mode (up to 400 kHz) or Fast-mode Plus (up to 1 MHz) I2C bus." RM0364 section 27.4 I2C functional description.

>how "I2C timing configuration tool " can help to set the timing reg in this situation ?

you can use STM32CubeMX for the configuration :

you can set 72MHz as a clock :

 

Hope I helped you!

Foued