Problem with IDIGI_FAT.C sample

Hi everybody,

I’m trying the IDIGI_FAT.C sample on a RCM6750 and I encouter the following problem :

First, I create one partition by using the FAT_SHELL.C sample, that’s great.
Then, I compile and run the IDIGI_FAT.C sample and it works very well, I can create files, list files and retrieve files, good.
The problem is : if I switch off the module (by cutting the power cord) and if I try to list and retrieve files, nothing is present, no files !!!

Where’s my mistake ?

Thanks in advance for your help.

The most likely problem here is the lack of battery backed RAM on the RCM6750. You need a certain amount of BBRAM for the FAT file system to work correctly when power is cycled.


I made the same test this morning with a little difference by connecting a CR2032 3V lithium battery to the VBAT_EXT pin and even after a power off and on cycle, I can retrieve my files.

Thanks for your help Peter

That’s good news, the FAT libs must be using the internal 32K of BBRAM on the R6000.


According to the online support, it seems this is a problem of synchronisation between the data stored in RAM and not flushed on the flash device before the cut off. An other way to fix it is to unmount and remount the serial flash device in order to synchronise.