How to make a small ram area used specially: cleared when powerup, not cleared when restart, read/write normally in normal

Hello Jays,

You can use the EEPROM or Hibernate BBRAM for such purpose. The EEPROM will maintain the data even after a power cycle, so when doing a power cycle the software must check the RESC register in System Control and clear the EEPROM.

Regards
Amit

Amit, thanks a lot about BBRAM advice, it looks like what i need.
EEPROM being used as event log, BBRAM not used before.
I've thought of using Heap area to malloc the expected variable since it's now defined as 0. Also the *.cmd file is considered to change some area to get a small area inserted.
thanks!

Hello Jays,

Do note that BBRAM may not be clear at Power Up. You would still need to establish that if it a POR w/o Hibernate then application program must clear the BBRAM.

Regards
Amit

Hi amit,
just checked the HIB part, seems that it must be enabled with 32K clk, but we've designed without it. Is there any solutions?

Regards
jays

Hello Jays,

Which TM4C12x device is it?

Regards
Amit

Hi,

It's TM4C123GE6PZT.

Regards
Jays

Hello Jays,

So the LFIOSC option is not there on TM4C123 parts (only kept for TM4C129). So the most effective option would be to have the EEPROM as storage. Alternatively, the TM4C123 device may need to be told via the cmd file that instead of 32Kbytes of SRAM, only 32K-N bytes of SRAM is available for application with explicit read/write access by the CPU to N byte locations. It may not be erased at BOR/WDT/Pad Reset and the SW needs to clear it explicitly under these conditions.

Regards
Amit