SLAZ162J October   2012  – May 2021 MSP430F2131

 

  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.      DGV20
      2.      PW20
      3.      DW20
      4.      RGE24
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  BCL6
    2. 6.2  BCL8
    3. 6.3  BCL9
    4. 6.4  BCL10
    5. 6.5  BCL11
    6. 6.6  BCL12
    7. 6.7  BCL13
    8. 6.8  BCL14
    9. 6.9  BSL5
    10. 6.10 CPU4
    11. 6.11 CPU5
    12. 6.12 CPU6
    13. 6.13 CPU11
    14. 6.14 CPU12
    15. 6.15 CPU13
    16. 6.16 CPU14
    17. 6.17 CPU19
    18. 6.18 CPU45
    19. 6.19 EEM20
    20. 6.20 FLASH16
    21. 6.21 FLASH17
    22. 6.22 FLASH18
    23. 6.23 FLASH19
    24. 6.24 FLASH20
    25. 6.25 FLASH22
    26. 6.26 FLASH24
    27. 6.27 FLASH27
    28. 6.28 FLASH36
    29. 6.29 JTAG15
    30. 6.30 PORT8
    31. 6.31 PORT10
    32. 6.32 SYS15
    33. 6.33 TA12
    34. 6.34 TA16
    35. 6.35 TA21
    36. 6.36 TAB22
    37. 6.37 XOSC5
    38. 6.38 XOSC8
  7. 7Revision History

BCL12

BCL Module

Category

Functional

Function

Switching RSELx or modifying DCOCTL can cause DCO dead time or a complete DCO stop

Description

After switching RSELx bits (located in register BCSCTL1) from a value of >13 to a value of <12 OR from a value of <12 to a value of >13, the resulting clock delivered by the DCO can stop before the new clock frequency is applied. This dead time is approximately 20 us. In some instances, the DCO may completely stop, requiring a power cycle.

Furthermore, if all of the RSELx bits in the BSCTL1 register are set, modifying the DCOCTL register to change the DCOx or the MODx bits could also result in DCO dead time or DCO hang up.

Workaround

- When switching RSEL from >13 to <12, use an intermediate frequency step. The intermediate RSEL value should be 13.


GUID-20201119-CA0I-XBDP-MZKL-BHL9R3DNGZ9X-low.png


AND

- When switching RSEL from <12 to >13 it's recommended to set RSEL to its default value first (RSEL = 7) before switching to the desired target frequency.

AND
- In case RSEL is at 15 (highest setting) it's recommended to set RSEL to its default value first (RSEL = 7) before accessing DCOCTL to modify the DCOx and MODx bits. After the DCOCTL register modification the RSEL bits can be manipulated in an additional step.

In the majority of cases switching directly to intermediate RSEL steps as described above will prevent the occurrence of BCL12. However, a more reliable method can be implemented by changing the RSEL bits step by step in order to guarantee safe function without any dead time of the DCO.

Note that the 3-step clock startup sequence consisting of clearing DCOCTL, loading the BCSCTL1 target value, and finally loading the DCOCTL target value as suggested in the in the "TLV Structure" chapter of the MSP430x2xx Family User's Guide is not affected by BCL12 if (and only if) it is executed after a device reset (PUC) prior to any other modifications being made to BCSCTL1 since in this case RSEL still is at its default value of 7. However any further changes to the DCOx and MODx bits will require the consideration of the workaround outlined above.