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DS80PCI402: DS80PCI402 Smbus EEPROM Access

Boby Joseph
Prodigy 70 points
Part Number: DS80PCI402


Hi,

We are using the DS80PCI402 in our design. We are operating the  DS80PCI402 in master mode by keeping the ENSMB flaoting.

When the board is powered up and either EEPROM is blank or the first byte data  is 0xFF , then there is continuous Smbus access happening to read the EEPROM.

If the EEPROM is programmed with configuration data, then repeater reads the EEPROM and stop the SMbus access after loading the configuration.

Is it the expected behavior for continuous SMBus access when the EEPROM is blank or first byte is oxFF?

Another issue is that EEPROM first bytes (0-4) get corrupted sometimes, can the repeater corrupt the EEPROM while doing the read access?

I have checked the I2C timings, it is meeting the spec as given in datasheet.

Regards,

Amit Mittal

 

  • 0
    TI__Mastermind 43795 points

    Hi Amit,

    Yes, the DS80PCI402 will continuously look for the EEPROM data making repeated attempts if the EEPROM is blank and the ENSMB pin = Float.

    The DS80PCI402 reading the EEPROM will not corrupt the EEPROM data during the configuration read.  Is the WP pin controlled to protect from false write operations?

    Regards,

    Lee

  • 0 in reply to Lee Sledjeski
    Prodigy 70 points
    Hi Lee,

    My observation is that when the DS80PCI402 is continuously accessing the EEPROM, even if I de-assert the READ_EN signal, then also SMbus access does not stop. So does it mean that once the READ_EN is asserted on power-up, then SMBus access will stop only when the DS80PCI402 will load the configuration data from EEPROM.

    Is there any other way to stop the SMBus access when the EEPROM is blank?


    Regards,
    Amit Mittal
  • 0 in reply to Boby Joseph
    TI__Mastermind 43795 points

    Hi Amit,

    To stop the SMBus access I would try to keep ENSMB = H when the EEPROM is blank.

    Regards,

    Lee