This application note describes the usage of file I/O
functions using Microchip’s memory disk drive file
system library. Microchip’s memory disk drive file
system is:
• Based on ISO/IEC 9293 specifications
• Known as the FAT16 file system, used on earlier
DOS operating systems by Microsoft
®
Corporation
• Also supports the FAT32 file system
• Most popular file system with SD (Secure
Digital) card, CF (CompactFlash
®
) card and USB
thumb drive
Most SD cards and MMCs (MultiMedia Cards), particu-
larly those sized below 2 gigabytes (GBs), use the
FAT16 standard. The FAT32 standard can be used to
address memory sized between 2 gigabytes and
2 terabytes. This application note provides a method to
read and/or write to these storage devices through a
microcontroller. The data of these storage devices can
be read by a PC, and the data written by a PC can be
read by a microcontroller. Most operating systems (i.e.,
Windows
®
XP) support the FAT16 and FAT32 file
systems. AN1045
Implementing File I/O Functions Using Microchip’s Memory
Disk Drive File System Library
Authors: Peter Reen and Naveen Mohanswamy INTERFACE
Microchip Technology Inc. The PICtail Daughter Board for SD and MMC,
Microchip product number AC164122, provides an
INTRODUCTION interface between SD or MMC and a
This application note describes the usage of file I/O PIC microcontroller through the Serial Peripheral
functions using Microchip’s memory disk drive file Interface (SPI) bus. The PICtail Daughter Board……
