SLAZ552W September   2014  – May 2021 MSP430FR4131

 

  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.      DGG48
      2.      DGG56
      3.      PM64
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC39
    2. 6.2  ADC50
    3. 6.3  ADC63
    4. 6.4  CPU21
    5. 6.5  CPU22
    6. 6.6  CPU40
    7. 6.7  CPU46
    8. 6.8  CS11
    9. 6.9  CS13
    10. 6.10 EEM23
    11. 6.11 EEM28
    12. 6.12 EEM30
    13. 6.13 GC1
    14. 6.14 GC4
    15. 6.15 GC5
    16. 6.16 PMM32
    17. 6.17 PORT28
    18. 6.18 RTC15
    19. 6.19 SYS23
    20. 6.20 USCI41
    21. 6.21 USCI42
    22. 6.22 USCI45
    23. 6.23 USCI47
    24. 6.24 USCI50
  7. 7Revision History

6.20 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.