MSP430F6749: I2C clock of UCB0SCL stop when read data from EEPROM

Emad Hamdy

Part Number: MSP430F6749

dear all

Iam Emad Hamdy hardware engineer in El sewedy Electrometer Egypt branch , and we have used MSP430F67491A MCU in a single phase meter design, and we faced problem in the communication with EEPROM using UCB0 port , the problem in the last byte of frame and after ACK the clock doesn't stop and generate extra 5 clocks and the SDA latched low, i attched pic for this case and and file

over 5 years ago

0 James Evans over 5 years ago

TI__Mastermind 49692 points

Hi Emad,

Thanks for your post. Unfortunately, I'm unable to access your attachment since it's in .rar format. Could you reattach any scopeshots showing this behavior?

Can you give more background information about how this issue started? Is this an existing design and something was changed in the code or the BOM that may have caused this or is this a new design and hence a new issue?

In the meantime, please read through the MSP430F6749's erratasheet. Unfortunately, there are several eUSCI-related errata. Specifically, USCI36 mentions UCLKI is not usable in I2C master mode for EUSCIB. Also, please read through the I2C section in the Solutions to Common eUSCI and USCI Serial Communication Issues on MSP430 MCUs app note.

Regards,

James

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MSP430F6749: I2C clock of UCB0SCL stop when read data from EEPROM