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

USB10

USB Module

Category

Functional

Function

USB interface may begin to endlessly transmit to the USB host when a rare timing event occurs between the USB host and MSP430 software execution

Description

When the host sends a SETUP packet for an IN transaction, the SETUPIFG bit always gets set by hardware, and the USB ISR is triggered.  While SETUPIFG is high, the host's attempts to continue the transaction with IN packets are automatically NAKed.  

When the SETUP packet has been decoded and the IN data prepared, the USB ISR clears the SETUPIFG bit. But if it happens to do so within the 2nd CRC bit of an IN packet from the host, the USB module enters an errant state and can begin to endlessly transmit to the host, irrespective of the protocol. The errant state can be cleared by resetting the module with the USB_EN bit; but there's no way for software to reliably detect the condition.

Since the 2nd CRC bit is only an 83ns window, the problem is extremely rare. However, since the timing of IN packets relative to their preceding SETUP packets can vary according to the host's timing, there's no way to ensure for certain that it will never happen.

Workaround

If the problem behavior occurs, and if the MSP430 is bus-powered, the user may naturally unplug/re-plug the devices USB connection.  If this occurs, the behavior will be corrected because power to the MSP430 will be cycled.  After this, its unlikely the problem will occur again soon, since the failure is usually rare.  

The behavior can be prevented altogether by clearing the UBME bit immediately before clearing SETUPIFG, and setting it again immediately after:  


        USBIEPCNF_0 &= ~EPCNF_UBME; // Clear ME to gate off SETUPIFG clear event
        USBOEPCNF_0 &= ~EPCNF_UBME; // Clear ME to gate off SETUPIFG clear event
        USBIFG &= ~SETUPIFG; // clear the interrupt bit
        USBIEPCNF_0 |= EPCNF_UBME; // Set ME to continue with normal operation
        USBOEPCNF_0 |= EPCNF_UBME; // Set ME to continue with normal operation



This workaround is reliable and effective.  However, as a side effect, it results in the creation of orphan tokens on the USB interface.  Although the workaround is field-tested, and no problems have been reported with these orphan packets, it is recommended to use the workaround only if the errata behavior is problematic for the application in question.