FatFs is a generic FAT/exFAT file system module for small embedded systems. The FatFs module is written in compliance with ANSI C (C89) and completely separated from the disk I/O layer. Therefore it is independent of the platform. It can be incorporated into small microcontrollers with limited resource, such as 8051, PIC, AVR, ARM, Z80, 78K and etc.


  • Windows compatible FAT/exFAT file system.
  • Platform independent. Easy to port.
  • Very small footprint for program code and work area.
  • Various configuration options to support for:
  • Multiple volumes (physical drives and partitions).
  • Multiple ANSI/OEM code pages including DBCS.
  • Long file name in ANSI/OEM or Unicode.
  • exFAT file system.
  • RTOS envilonment.
  • Fixed or variable sector size.
  • Read-only, optional API, I/O buffer and etc…