The KW40Z datasheet specifies an I2C speed of up to 1Mbps under section 2.5 Peripheral Interfaces. However, under section 188.8.131.52, table 34 it indicates a maximum SCL clock frequency of 400kHz. Does the KW40Z support I2C high speed mode at 1Mbps?
I hope you're doing well. Thank you for your question. Regarding the timing of the I2C you can see that in Standard Mode the maximum value is equal to 100kHz while in Fast Mode you can reach 400 kHz, you can confirm this info in the table you mentioned, however the inter-integrated circuit module provides a method of communication between a number of devices. The device is capable of operating at higher baud rates, up to a maximum of bus clock/20, with reduced bus loading even if the interface is designed to operate at up to 100 kbit/s with maximum bus loading and timing.
To make this clear this module does not have a special circuit to pull up the SCL and SDA lines to achieve high speed mode (up to 3.4MHz) compliance, although you may set the maximum baud rate of the I2 C module up to bus clock/20. This setting would be up to you.
I hope this information helps.
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