SLAZ184P October   2012  – May 2021 MSP430F249 , MSP430F249-EP

 

  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.      PM64
      2.      RGC64
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC25
    2. 6.2  BCL12
    3. 6.3  BCL13
    4. 6.4  BCL15
    5. 6.5  COMP2
    6. 6.6  CPU19
    7. 6.7  FLASH19
    8. 6.8  FLASH24
    9. 6.9  FLASH25
    10. 6.10 FLASH27
    11. 6.11 FLASH36
    12. 6.12 JTAG23
    13. 6.13 PORT11
    14. 6.14 PORT12
    15. 6.15 TA12
    16. 6.16 TA16
    17. 6.17 TA21
    18. 6.18 TAB22
    19. 6.19 TB2
    20. 6.20 TB16
    21. 6.21 TB24
    22. 6.22 USCI20
    23. 6.23 USCI21
    24. 6.24 USCI22
    25. 6.25 USCI23
    26. 6.26 USCI24
    27. 6.27 USCI25
    28. 6.28 USCI26
    29. 6.29 USCI28
    30. 6.30 USCI30
    31. 6.31 USCI34
    32. 6.32 USCI35
    33. 6.33 USCI40
    34. 6.34 XOSC5
    35. 6.35 XOSC6
    36. 6.36 XOSC8
  7. 7Revision History

6.9 FLASH25

FLASH Module

Category

Functional

Function

Marginal Read Mode is not functional

Description

The control bits for marginal read mode contained in the FCTL4 register are automatically cleared by any flash access. This prevents the marginal read mode from being used.

Workaround

It is possible to read out memory contents in marginal read mode if the indexed addressing mode X(Ry) is used to access the flash memory. In this case, the FCTL4 control bits are not cleared, and the marginal read mode works as expected. It is recommended to write the code for reading the flash memory contents in assembler as this allows full control over the used addressing mode. Note that certain assemblers may optimize an indexed addressing source operation of 0(Ry) to an indirect register mode @Ry operation, which will not work. The following is an example of reading the word memory location 0x4000 in marginal read mode, preventing a possible assembler optimization:

mov.w #0x4000,R15   ; Pointer to target address
dec.w R15           ; Decrement pointer
mov.w 1(R15),R12    ; Read memory contents at R15+1, store result in R12