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MSP430F477 Errata

koksal ocal71549
Prodigy 40 points

Dear All,

Could you please help us to understand following errata statement clearly.

Referring to the document "MSP430F47x Device Erratasheet",

Does the statement

"When a flash write or erase is abruptly terminated, any further reliable reads by the flash

controller are not ensured. The abrupt termination can be the result of one the following

events:" means that the flash is dead any more  or is the flush not functional temporarirly and if yes when will  the normal operation of flash restore?

The reason why we are asking is the abrupt termination of the flash could also  occur in the case of a power failure and under a strong EMI exposure which are unavoidable most of the time. 

Regards,

 

 

 

  • 0
    Expert 1170 points

    Well, my understanding is that TI tries to say that if a Flash cell is programmed (data is written into the Flash cell) or erased (Flash cells of a complete segment is erased) and you terminate the programming or erasing the content within the accessed Flash cell is not reliable anymore. Means the '1' or '0' that was written into the Flash Cell is not reliable programmed.

    Power failures or strong EMI is a different condition that may cause other issues.

  • 0 in reply to Voyager
    Prodigy 40 points

    Thanks Voyager

    If it is so, than it is OK. but the statement "any further reliable reads by the flash

    controller are not ensured " seemed to me like a more general issue than a special problem occured in the segment being written at the time of termination. 

  • 0 in reply to koksal ocal71549
    Guru 227245 points

    koksal ocal71549 said:
    the statement "any further reliable reads by the flash controller are not ensured " seemed to me like a more general issue than a special problem occured in the segment being written at the time of termination.


    Indeed, it shoudl rather read 'of the currently programmed cell' or 'of the currently programmed block'.

    The reason is that the programming voltage is applied to a block at once (al other blocks are 'safe'), and interrupting the programming process leaves at least the currently programmed cell (and maybe thw whole block, sicne this is an abnormal termination of the programming procedure, inlcudign the deactivation of the programming voltage that is attached to the whole block) in an uncertain state. Maybe the next read is showignm the correct result, but after a minute or a day, the cell falls back below the threshold and reads '1' again where it was programmed '0'.

    The flash controller itself will still work and all cells/blocks/segments which did not have the programming voltage applied, are unaffected.
    Also, any 'damage' done to the block wil be nullified after an additional erase cycle (ore more cycles, depending on the family), so after the condition that caused the emergency exit is solved, you can reporgram the segment.

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