SLAZ627W September   2014  – August 2021 MSP430FR6972

 

  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.      PM64
      2.      RGC64
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC38
    2. 6.2  ADC42
    3. 6.3  ADC43
    4. 6.4  ADC64
    5. 6.5  ADC66
    6. 6.6  ADC67
    7. 6.7  ADC69
    8. 6.8  ADC70
    9. 6.9  ADC71
    10. 6.10 AES1
    11. 6.11 COMP7
    12. 6.12 COMP10
    13. 6.13 CPU21
    14. 6.14 CPU22
    15. 6.15 CPU40
    16. 6.16 CPU46
    17. 6.17 CPU47
    18. 6.18 CS7
    19. 6.19 CS12
    20. 6.20 DMA7
    21. 6.21 EEM19
    22. 6.22 EEM23
    23. 6.23 EEM27
    24. 6.24 EEM30
    25. 6.25 EEM31
    26. 6.26 GC4
    27. 6.27 GC5
    28. 6.28 JTAG27
    29. 6.29 PMM24
    30. 6.30 PMM27
    31. 6.31 PMM31
    32. 6.32 PMM32
    33. 6.33 PORT28
    34. 6.34 REF9
    35. 6.35 RTC10
    36. 6.36 RTC12
    37. 6.37 TB25
    38. 6.38 USCI41
    39. 6.39 USCI42
    40. 6.40 USCI45
    41. 6.41 USCI47
    42. 6.42 USCI50
  7. 7Revision History

6.38 USCI41

USCI Module

Category

Functional

Function

UCBUSY bit of eUSCIA module might not work reliable when device is in SPI mode.

Description

When eUSCIA is configured in SPI mode, the UCBUSY bit might get stuck to 1 or start toggling after transmission is completed. This happens in all four combinations of Clock Phase and Clock Polarity options (UCAxCTLW0.UCCKPH & UCAxCTLW0.UCCKPL bits) as well as in Master and Slave mode. There is no data loss or corruption. However the UCBUSY cannot be used in its intended function to check if transmission is completed.  Because the UCBUSY bit is stuck to 1 or toggles, the clock request stays enabled and this adds additional current consumption in low power mode operation.

Workaround

For correct functional implementation check on transmit or receive interrupt flag UCTXIFG/UCRXIFG instead of UCBUSY to know if the UCAxTXBUF buffer is empty or ready for the next complete character.
To reduce the additional current it is recommended to either reset the SPI module (UCAxCTLW0.UCSWRST) in the UCBxCTLW0  or send a dummy byte 0x00 after the intended SPI transmission is completed.