SLAZ242O October   2012  – May 2021 MSP430F4784

 

  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  COMP3
    2. 6.2  CPU19
    3. 6.3  CPU44
    4. 6.4  EEM20
    5. 6.5  FLASH19
    6. 6.6  FLASH24
    7. 6.7  FLASH25
    8. 6.8  FLASH27
    9. 6.9  FLASH36
    10. 6.10 FLL4
    11. 6.11 FLL5
    12. 6.12 FLL6
    13. 6.13 FLL7
    14. 6.14 JTAG23
    15. 6.15 LCDA5
    16. 6.16 LCDA7
    17. 6.17 SDA4
    18. 6.18 TA12
    19. 6.19 TA16
    20. 6.20 TA21
    21. 6.21 TAB22
    22. 6.22 TB2
    23. 6.23 TB16
    24. 6.24 TB24
    25. 6.25 USCI15
    26. 6.26 USCI19
    27. 6.27 USCI20
    28. 6.28 USCI21
    29. 6.29 USCI22
    30. 6.30 USCI23
    31. 6.31 USCI24
    32. 6.32 USCI25
    33. 6.33 USCI26
    34. 6.34 USCI28
    35. 6.35 USCI30
    36. 6.36 USCI34
    37. 6.37 USCI35
    38. 6.38 USCI40
    39. 6.39 XOSC5
    40. 6.40 XOSC8
    41. 6.41 XOSC9
  7. 7Revision History

6.27 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