SLAZ234O October   2012  – May 2021 MSP430F47186

 

  1. 1Functional Advisories
  2. 2Preprogrammed Software Advisories
  3. 3Debug Only Advisories
  4. 4Fixed by Compiler Advisories
  5. 5Nomenclature, Package Symbolization, and Revision Identification
    1. 5.1 Device Nomenclature
    2. 5.2 Package Markings
      1.      PZ100
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  CPU19
    2. 6.2  CPU44
    3. 6.3  DMA3
    4. 6.4  DMA4
    5. 6.5  DMA13
    6. 6.6  EEM20
    7. 6.7  FLASH19
    8. 6.8  FLASH24
    9. 6.9  FLASH27
    10. 6.10 FLL3
    11. 6.11 FLL8
    12. 6.12 JTAG23
    13. 6.13 LCDA5
    14. 6.14 LCDA6
    15. 6.15 LCDA7
    16. 6.16 TA12
    17. 6.17 TA16
    18. 6.18 TA21
    19. 6.19 TAB22
    20. 6.20 TB2
    21. 6.21 TB16
    22. 6.22 TB24
    23. 6.23 USCI20
    24. 6.24 USCI21
    25. 6.25 USCI22
    26. 6.26 USCI23
    27. 6.27 USCI24
    28. 6.28 USCI25
    29. 6.29 USCI26
    30. 6.30 USCI28
    31. 6.31 USCI30
    32. 6.32 USCI34
    33. 6.33 USCI35
    34. 6.34 USCI40
    35. 6.35 XOSC5
    36. 6.36 XOSC8
    37. 6.37 XOSC9
  7. 7Revision History

6.23 USCI20

USCI Module

Category

Functional

Function

I2C Mode Multi-master transmitter issue

Description

When configured for I2C master-transmitter mode, and used in a multi-master environment, the USCI module can cause unpredictable bus behavior if all of the following four conditions are true:

1 - Two masters are generating SCL
And
2 - The slave is stretching the SCL low phase of an ACK period while outputting NACK on SDA
And
3 - The slave drives ACK on SDA after the USCI has already released SCL, and then the SCL bus line gets released
And
4 - The transmit buffer has not been loaded before the other master continues communication by driving SCL low

The USCI will remain in the SCL high phase until the transmit buffer is written. After the transmit buffer has been written, the USCI will interfere with the current bus activity and may cause unpredictable bus behavior.

Workaround

1 - Ensure that slave doesn't stretch the SCL low phase of an ACK period
Or
2 - Ensure that the transmit buffer is loaded in time
Or
3 - Do not use the multi-master transmitter mode