Hi Arslan,
Sorry for the delayed response.
The TI-RTOS FatFs module uses the R0.08 release of FatFs. This module supports Fat12, Fat16 and Fat32 file systems.
The reason you are seeing odd behavior is that SDHC cards use the Fat file system (Fat12, Fat16, Fat32) but SDXC cards actually use a patented proprietary exFAT file system. It is possible that this new format is NOT backwards compatible.
Additionally, the SDSPI driver has not been tested on exFAT. There may be some changes required to support exFAT, so trying to use it on exFAT will result in unexpected behavior.
Regards,
-- Emmanuel