MSPM0G3507: MSPM0G3507 Flash operations

Manikanth Chintoju

Part Number: MSPM0G3507

Tool/software:

Hi TI,

I've observed a scenario.

First I'm erasing the sector where I'm intended to write. So after erase that sector area which it belongs to will be locked(according to datasheet) but I'm locking all the regions explicitly by giving maximum to PROT A,B,C. My interest is only Main flash area no bootloader nothing.

FLASHCTL->GEN.CMDWEPROTA = FLASHCTL_CMDWEPROTA_VAL_MASK | FLASHCTL_CMDWEPROTA_VAL_MAXIMUM;

FLASHCTL->GEN.CMDWEPROTB = FLASHCTL_CMDWEPROTB_VAL_MASK | FLASHCTL_CMDWEPROTB_VAL_MAXIMUM;

FLASHCTL->GEN.CMDWEPROTC = FLASHCTL_CMDWEPROTC_VAL_MASK | FLASHCTL_CMDWEPROTC_VAL_MAXIMUM;

Then I'm blank verifying the region if it's true then I'm trying to write some data in this write api when I'm check if the flash is locked or not then I'm getting it as false

return ((FLASHCTL->GEN.CMDWEPROTA == FLASHCTL_CMDWEPROTA_VAL_MAXIMUM)

&& (FLASHCTL->GEN.CMDWEPROTB == FLASHCTL_CMDWEPROTB_VAL_MAXIMUM)

&& (FLASHCTL->GEN.CMDWEPROTC == FLASHCTL_CMDWEPROTC_VAL_MAXIMUM));

Why lock is not happening.

Also why the last 8 bytes of the flash is not accesible for operations..?

4 months ago

0 Pengfei Xie 4 months ago

TI__Expert 8355 points

Hi,

I did the same test with you. Here is the results:

As you are using MSPM0G3507 device, the flash is single bank and flash size is 128KB (128 sectors).

So the CMDWEPROTA is for sector 1 ~ sector 32, and CMDWEPROTB is for sector 33~ sector 128. So only the low 12bits of CMDWEPROTB is used and each bit for 8 sectors. And the other unused bits of CMDWEPROTB and CMDWEPROTC is not valid.

0 Manikanth Chintoju 4 months ago in reply to Pengfei Xie

Prodigy 85 points

Got it the check mechanism which I'm doing is wrong. Thanks for the clarification.

Why the last 8bytes of flash is not accessible? What is the exact reason for it..?

0 Pengfei Xie 4 months ago in reply to Manikanth Chintoju

TI__Expert 8355 points

Hi,

It is because that, in MSPM0, when CPU executes program, it will prefetch the flash data of next flash word (8Byte). So if there is program in the last flash word, there may be exception because of incorrect access of flash address.

0 Manikanth Chintoju 4 months ago in reply to Pengfei Xie

Prodigy 85 points

So if it's code flash then it will give the prefetch issue right. But I want to use that last sectors also for storing some data. which is not a command or a part of code. Just some data. You can assume like data log information. So can I use the last 8bytes as well because If I omit last 8 bytes and perform flash operations then sector alignment etc might fail right..?

0 Manikanth Chintoju 4 months ago in reply to Manikanth Chintoju

Prodigy 85 points

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MSPM0G3507: MSPM0G3507 Flash operations