I2C peripheral lowest possible data rate

Hmm.

Well you have to set the I2C clock prescaler so that the internal module clock is between 6.7MHz and 13.x MHz according to the TRM. I know that this is a requirement or else some of the timings that are derived from this clock are not met by the IP.

But - after that there is a 16 bit divider for clock low time, and another for clock high time.

If I do the math - 6,700,000 Hz / 128,010 = about 50Hz roughly.. so I am not sure where the 10KHz min comes from.

I'd say work with the datasheet and assume it can go to 0Hz if the slave extends and down to whatever the divider says.
But that is just advice because parameter table trumps high level bullet in my own opinion.

-Anthony

Hi Josh,

So I may have a theory.  

Our internal spec from the TMS470 didn't have a 10KHz statement.   But we used a different branch of the IP (from the C5000 DSP) for the TMS570.   This spec has the 10KHz statement but it's on a feature bullet and in () it says 'phillips standard' ...  so it's just saying in effect that these numbers come from the standard.

I did find something in the Philips standard that may be the root of the 10Khz and it's the most likely thing I've found.

There is a section comparing SMBUS and I2C and it states:

"4.2.1 I2C/SMBus compliancy

SMBus and I2C protocols are basically the same: A SMBus master is able to control I2C

devices and vice versa at the protocol level. The SMBus clock is defined from 10 kHz to

100 kHz while I2C can be 0 Hz to 100 kHz, 0 Hz to 400 kHz, 0 Hz to 1 MHz and

0 Hz to 3.4 MHz, depending on the mode. This means that an I2C-bus running at less

than 10 kHz is not SMBus compliant since the SMBus devices may time-out."

That may be where the 10KHz originated from.    But again it's clear we say we support down to 0Hz

in the electrical spec,  and we can configure out clock down to 50Hz approximately - so I would say those are solid compared to just a bullet in the feature list.