TMS570LS1114: Emulated EEPROM / Overwriting instead of erasing in order to save time

Sebastian Schöler

Part Number: TMS570LS1114

Dear support forum,

regarding the emulated EEPROM inside the TMS570LS family, we might face issues regarding the timing requirements:

The worst case time for a sectore erase of 8 s is simply to high.
Therefore, we think about "overwriting" the sector instead of erasing it and also store information of the memory position at which the important / new information starts.

=> The first question would be if this is possible or if a sector needs to be erased before being programmes again / overwritten.

=> The second question would be if erase of one sector and writing of another sector inside the BANK7 emulated EEPROM is possible. For BANKS this seems to be possible, but I am not sure regarding the sectors inside a bank.

Kind regards
Sebastian

over 1 year ago

0 jagadish gundavarapu over 1 year ago

TI__Guru 69891 points

Hi Sebastian,

Regarding more details about 8Sec erase time you can refer below thread:

(+) TMS570LS1227: Data flash erase times - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Sebastian Schöler said:
=> The first question would be if this is possible or if a sector needs to be erased before being programmes again / overwritten.

Generally, NOR flash memory organized into sectors, each of which consists of certain number of pages. Each page consists of certain number of bytes. Before new data can be written to a sector, the entire sector must be erased. This is because NOR flash memory can only be programmed by setting a bit from 1 to 0, but to set a bit from 0 to 1 the entire sector must be erased first.

Sebastian Schöler said:
=> The second question would be if erase of one sector and writing of another sector inside the BANK7 emulated EEPROM is possible. For BANKS this seems to be possible, but I am not sure regarding the sectors inside a bank.

Yes, it is possible for sectors as well.

I mean you can use TI FEE driver for this case. Actually, in this driver the physical sectors are converted into virtual sectors and min of two virtual sectors will be needed for FEE operation. What happens here is the data is written in first virtual sector and once the first sector is filled with complete data then this sector will be go for erase in background and new data will be written to the second virtual sector and if second virtual sector got filled then again data will be written into the first virtual sector and this process will continue.

I guess this would be very useful for your requirement.

To understand more about FEE driver please refer below guide and threads:

1411.TI FEE User Guide.pdf

(+) TMS570LS3137: Regarding FEE_BLOCK_CONFIGURATION IN FEE_EEPROM - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) TMS570LS1224: Questions about the FEE concept - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

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Thanks & regards,
Jagadish.

0 Sebastian Schöler over 1 year ago in reply to jagadish gundavarapu

Prodigy 230 points

Hey Jagadish,

thank you for the fast reply!
One last question: During write and espescially erasure procedure: What happens if the MCU is reset by an external watchdog DURING the operation? Are the drivers designed to be robust in such a case?

Kind regards
Sebastian

0 jagadish gundavarapu over 1 year ago in reply to Sebastian Schöler

TI__Guru 69891 points

Hi Sebastian,

Sebastian Schöler said:
What happens if the MCU is reset by an external watchdog DURING the operation? Are the drivers designed to be robust in such a case?

FEE driver designed in such way that it is robust to the all power failures(that includes watchdog reset aswell).

Please review the power fail behavior in user guide.

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Thanks & regards,
Jagadish.