MSPM0L1304: Flash content after erasure

Michael Walle

Part Number: MSPM0L1304

Tool/software:

Hi,

according to the TRM the flash content is not deterministic (ch. 6.3.4 ERASE Command):

Note
After erasure, the memory contents of a sector are not deterministic until programmed. Erased bits do
not always read as 1 after an erase. A memory location must be successfully programmed using the
PROGRAM command before the memory location can be considered deterministic.

But according to a forum post regarding a similar uC (https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1429418/mspm0g3107-blank-check-on-uninitialized-memory-not-working/5481370) one "expect a value of 0xFF every time you erase a location in flash".

What's true now? Also, can I repogram an already programmed page? Of course only bits will flip from 1 to 0. 0 bits will remain 0.

I'm asking because I want to use the flash idiom where you have some kind of header, let's say 0xff followed by some data. To invalidate the data you just write the header byte to 0, for example.

Thanks,
-michael

8 months ago

0 Zoey Wei 8 months ago

TI__Genius 10611 points

Hi Michael,

The FLASH will be 0xFF after your erasure.

For using, please refer to our SDK.

Thanks,

Zoey

0 Michael Walle 8 months ago in reply to Zoey Wei

Prodigy 130 points

Hi Zoey,

what about my question about reprogramming the flash? Also, can you confirm the TRM is wrong regarding the erasure?

Thanks,
-michael

0 Zoey Wei 8 months ago in reply to Michael Walle

TI__Genius 10611 points

Hi Michael,

What the TRM indicates is that after executing the erase command, the erase may not succeed. However, if your erase times are within the specs range indicated in the datasheet, the erase is guaranteed to succeed, which is 0xFF.

And for reprogramming, of course you can reprogram the flash which is not erased before.

Regards,

Zoey

0 Michael Walle 8 months ago in reply to Zoey Wei

Prodigy 130 points

Hi Zoey,

sorry, but this is not what the note is talking about. It clearly says, that after an erase the bits are in a non deterministic state. It's not talking about any non-compliant erasures. Therefore, either the 0xff is wrong or the TRM. I'd like to know which is.

Zoey Wei said:
And for reprogramming, of course you can reprogram the flash which is not erased before.

Thanks for confirming.

Thanks,
-michael

0 Zoey Wei 8 months ago in reply to Michael Walle

TI__Genius 10611 points

Hi Michael,

From the beginning to now, I have not seen any customer say that the data will not be erased to 0xFF. Based on what is said in the TRM, I can help you consult internally.

Regards,

Zoey

0 Michael Walle 8 months ago in reply to Zoey Wei

Prodigy 130 points

Hi Zoey,

I'd appreciate if you could ask internally what that paragraph is about. Thanks!

Best regards,
-michael

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MSPM0L1304: Flash content after erasure