"The device is designed to operate up to 100 kHz! (SCL frequency)"

[PeterFromSweden]

Hi

I am using Processor Expert Driver suite 10.4.1 on kinetis k60 (and k64) targets.

For example document K64P144M120SF5 Data Sheet claims that I2C supports 1 Mbit/s, but when using the I2C_LDD component, I get a warning if SCL frequency is above 100 kHz.

Why cant I set higher without getting this warning?

Regards

/Peter

[mjbcswitzerland]

Peter

Philips' I2C specification limits the clock to 100kHz for operation within the maximum I2C bus topology (loading/length). The warning is probably there since the setting is beyond the basic standard and not that it can't or won't work.

Many I2C devices have an extended speed specification of 400kHz (high speed I2C) but it is probably rare to find one that is specified any higher than that (although again it may work, but could become unreliable if the distances or bus loading increases in the future).

Regards

Mark

[PeterFromSweden]

Mark

I think you refer to old Philips specifications. There are newer ones and the devices I use support not only fast mode (400 kbit/s), but also high speed mode (3.4 Mbit/s). So I want to know how to get rid of warning (gets attention every time do processor expert stuff)

See link below.

I2C Bus: Fast Mode

Regards

/Peter

[mjbcswitzerland]

Peter

I haven't used devices that support more than 400kHz yet, but I am indedd referring to the original specification and expect that the PE configuration is also doing so when deciding whether to display a warning or not.

If the warning can't be ignored I recommend requesting some form of setting to remove it to be added - PE has its own forum here: https://community.freescale.com/community/pex

or else enter a service request.

Maybe you can configure it to generate the I2C part only once and then not need to generate it again (?) I don't use PE myself so don't know details.

Regards

Mark