SLAZ657S February   2015  – May 2021 MSP430F6720A

 

  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.      PZ100
      2.      PN80
    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  AUXPMM2
    5. 6.5  BSL7
    6. 6.6  BSL14
    7. 6.7  CPU21
    8. 6.8  CPU22
    9. 6.9  CPU36
    10. 6.10 CPU40
    11. 6.11 CPU46
    12. 6.12 CPU47
    13. 6.13 DMA4
    14. 6.14 DMA7
    15. 6.15 DMA9
    16. 6.16 DMA10
    17. 6.17 EEM8
    18. 6.18 EEM17
    19. 6.19 EEM19
    20. 6.20 EEM23
    21. 6.21 JTAG26
    22. 6.22 JTAG27
    23. 6.23 LCDB5
    24. 6.24 LCDB6
    25. 6.25 PMM7
    26. 6.26 PMM11
    27. 6.27 PMM12
    28. 6.28 PMM14
    29. 6.29 PMM15
    30. 6.30 PMM18
    31. 6.31 PMM20
    32. 6.32 PMM26
    33. 6.33 PORT15
    34. 6.34 PORT19
    35. 6.35 SD3
    36. 6.36 UCS11
    37. 6.37 USCI36
    38. 6.38 USCI37
    39. 6.39 USCI41
    40. 6.40 USCI42
    41. 6.41 USCI47
    42. 6.42 USCI50
  7. 7Revision History

6.17 EEM8

EEM Module

Category

Debug

Function

Debugger stops responding when using the DMA

Description

In repeated transfer mode, the DMA automatically reloads the size counter (DMAxSZ) once a transfer is complete and immediately continues to execute the next transfer unless the DMA Enable bit (DMAEN) has been previously cleared. In burst-block transfer mode, DMA block transfers are interleaved with CPU activity 80/20% - of ten CPU cycles, eight are allocated to a block transfer and two are allocated for the CPU.

Because the JTAG system must wait for the CPU bus to be clear to halt the device, it can only do so when two conditions are met:
- Three clock cycles after any DMA transfer, the DMA is no longer requesting the bus.
and
- The CPU is not requesting the bus.

Therefore, if the DMA is configured to operate in the repeat burst-block transfer mode, and a breakpoint is set between the line of code that triggers the DMA transfers and the line that clears the DMAEN bit, the DMA always requests the bus and the JTAG system never gains control of the device.

Workaround

When operating the DMA in repeat burst-block transfer mode, set breakpoint(s) only when the DMA transfers are not active (before the start or after the end of the DMA transfers).