SLAZ312AD October   2012  – May 2021 MSP430F5527

 

  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.      PN80
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC25
    2. 6.2  ADC27
    3. 6.3  ADC29
    4. 6.4  ADC42
    5. 6.5  ADC69
    6. 6.6  BSL6
    7. 6.7  BSL7
    8. 6.8  COMP10
    9. 6.9  CPU21
    10. 6.10 CPU22
    11. 6.11 CPU23
    12. 6.12 CPU26
    13. 6.13 CPU27
    14. 6.14 CPU28
    15. 6.15 CPU29
    16. 6.16 CPU30
    17. 6.17 CPU31
    18. 6.18 CPU32
    19. 6.19 CPU33
    20. 6.20 CPU34
    21. 6.21 CPU35
    22. 6.22 CPU37
    23. 6.23 CPU39
    24. 6.24 CPU40
    25. 6.25 CPU47
    26. 6.26 DMA4
    27. 6.27 DMA7
    28. 6.28 DMA8
    29. 6.29 DMA10
    30. 6.30 EEM9
    31. 6.31 EEM11
    32. 6.32 EEM13
    33. 6.33 EEM14
    34. 6.34 EEM15
    35. 6.35 EEM16
    36. 6.36 EEM17
    37. 6.37 EEM19
    38. 6.38 EEM21
    39. 6.39 EEM23
    40. 6.40 FLASH33
    41. 6.41 FLASH34
    42. 6.42 FLASH35
    43. 6.43 FLASH37
    44. 6.44 JTAG20
    45. 6.45 JTAG26
    46. 6.46 JTAG27
    47. 6.47 MPY1
    48. 6.48 PMAP1
    49. 6.49 PMM9
    50. 6.50 PMM10
    51. 6.51 PMM11
    52. 6.52 PMM12
    53. 6.53 PMM14
    54. 6.54 PMM15
    55. 6.55 PMM17
    56. 6.56 PMM18
    57. 6.57 PMM20
    58. 6.58 PORT15
    59. 6.59 PORT16
    60. 6.60 PORT19
    61. 6.61 PORT24
    62. 6.62 RTC3
    63. 6.63 RTC6
    64. 6.64 SYS10
    65. 6.65 SYS12
    66. 6.66 SYS14
    67. 6.67 SYS16
    68. 6.68 SYS18
    69. 6.69 TAB23
    70. 6.70 USB4
    71. 6.71 USB6
    72. 6.72 USB8
    73. 6.73 USB9
    74. 6.74 USB10
    75. 6.75 USB11
    76. 6.76 USB12
    77. 6.77 USB13
    78. 6.78 USCI26
    79. 6.79 USCI30
    80. 6.80 USCI31
    81. 6.81 USCI34
    82. 6.82 USCI35
    83. 6.83 USCI39
    84. 6.84 USCI40
    85. 6.85 WDG4
  7. 7Revision History

USB8

USB Module

Category

Functional

Function

USB PLL may fail to initialize when DCO is not used

Description

If the DCO is not used or does not source any clock in the system, the PLL may not initialize properly, leading to a "bus error" NMI when the CPU attempts to access USB memory. Under certain conditions, the PLL requires the DCO to be active in order to initialize properly. If any of the system clocks (MCLK, SMCLK, ACLK) are derived from the DCO during PLL initialization, this condition is satisfied and the PLL initializes in a stable manner.

Workaround

- Configure one of the system clocks to use the DCO for normal operation.  (In most applications, it's convenient to source MCLK from the DCO.)

or

- If it's necessary to use a clock configuration that doesn't include the DCO, then briefly activate it, then de-activate it.  This should be done after setting the UPLLEN bit but before polling the USBPLLIR flags.  The code below shows a simplified PLL initialization procedure.  (In the MSP430 USB API Stacks, this is performed in USB_enable().)  

    USBPLLCTL |= UPLLEN;    // Enable PLL

    // Add the following code to enable the DCO, then immediately revert back
    // to the original clock settings for the application.  This is long
    // enough to allow PLL initialization to proceed.  The actual UCSCTL4
    // settings depend on the application's clock requirements.  

    UCSCTL4 = SELA__REFOCLK + SELS__XT2CLK + SELM__DCOCLK;  // Enable the DCO
    UCSCTL4 = SELA__REFOCLK + SELS__XT2CLK + SELM__XT2CLK;  // Revert back

    //Wait for the PLL to settle
    do {
        USBPLLIR    =     0x0000;  // Clear the flags
        for (i =0; i < 400; i++);  // Wait for flags to set if not stable yet
    }while (USBPLLIR != 0);

    // PLL is now stable