SLAZ484AD December   2012  – May 2021 MSP430F6749

 

  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.      PEU128
      2.      PZ100
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC39
    2. 6.2  ADC42
    3. 6.3  ADC69
    4. 6.4  AES1
    5. 6.5  AUXPMM1
    6. 6.6  AUXPMM2
    7. 6.7  BSL7
    8. 6.8  BSL14
    9. 6.9  COMP10
    10. 6.10 CPU21
    11. 6.11 CPU22
    12. 6.12 CPU36
    13. 6.13 CPU37
    14. 6.14 CPU40
    15. 6.15 CPU46
    16. 6.16 CPU47
    17. 6.17 DMA4
    18. 6.18 DMA7
    19. 6.19 DMA9
    20. 6.20 DMA10
    21. 6.21 EEM17
    22. 6.22 EEM19
    23. 6.23 EEM23
    24. 6.24 JTAG26
    25. 6.25 JTAG27
    26. 6.26 LCDB6
    27. 6.27 PMM11
    28. 6.28 PMM12
    29. 6.29 PMM14
    30. 6.30 PMM15
    31. 6.31 PMM18
    32. 6.32 PMM20
    33. 6.33 PMM26
    34. 6.34 PORT15
    35. 6.35 PORT19
    36. 6.36 PORT26
    37. 6.37 RTC8
    38. 6.38 SD3
    39. 6.39 SYS16
    40. 6.40 UCS11
    41. 6.41 USCI36
    42. 6.42 USCI37
    43. 6.43 USCI41
    44. 6.44 USCI42
    45. 6.45 USCI47
    46. 6.46 USCI50
  7. 7Revision History

6.43 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.