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TMS320F28069M: I2C max frequency

Jakub Klein
Intellectual 630 points
Part Number: TMS320F28069M


Hello,

In Piccollo Technical Reference Manual (spruh18, chapter 14), at the introduction to I2C module, there's an information:

"Two transmission speeds: Standard (100 Kbps) and Fast (400 Kbps)"

However Section 14.5.7.1 gives the formula to set master clock period to any value. I defined ICCH and ICCL to correspond with frequency of 800kHz (Tmst = 1/800,000) and everything seems to work fine, the frequency seen via logic analyzer is indeed 800kHz. The problems started to rise at 1000kHz (the SCL frequency was OK and slave address on SDA was valid, but no ACK obtained - so maybe it's a matter of my slave device).

The question is: how can I relate this information from module description to my experiment? Is it safe to use frequencies higher than 400kHz?

  • 0
    TI__Guru** 115971 points

    Hi Jakub,

    TI only supports what is mentioned in the document. This is based on the characterization done across PVT conditions. It may work at higher frq but TI does not guarantee that. I would recommend not to use at frq higher than what is mentioned in document.

    Regards,

    Vivek Singh

  • 0
    Guru 30330 points
    Jakub,

    The dividers allow for the clock to be configured to be higher, but the F2806x I2C is limited to speeds up to 400KHz. We cannot guarantee proper operation above that. I will clarify however that while we guarantee operation at any frequency up to 400 KHz, and it is not just limited to the two frequencies of 100KHz and 400KHz.

    Thanks,
    Mark