Media Types

Overview

FAT is designed to interface to any standard DOS-compatible device through standard interface routines (read_sector(), write_sector(), etc.).

Compatible media includes:

Features

    1. MMC, SD, SDHC and SDXC
    2. Compact Flash
    3. Atmel DataFlash
    4. NAND Flash
    5. RAM Drives

MMC, SD, SDHC and SDXC

This is probably the simplest method to add DOS-compatible file media to an embedded device. Code Time Technologies provides a range of drivers for interfacing to SD, SDHC, SDXC and MMC cards. Included are standard SPI, which is implemented in either hardware or software, and 4-bit data interfaces for controllers that support them.

Compact Flash

Compact Flash cards are more complex, but they offer performance advantages. This is due to the wider data bus, resulting in higher throughput, and in many cases reduced CPU loads.

Atmel DataFlash

Two driver types are provided for use with all types of Atmel DataFlash:

  1. A simple driver that does a direct mapping of DataFlash pages to the logical disk is provided as standard.
  2. A more complex driver that handles the DataFlash in a more reliable way may be ordered separately.

NAND Flash

A complete Flash Translation Layer provides a complete, reliable interface to NAND flash, and may be combined with FAT.

RAM Drive

A RAM drive is provided as standard and is particularly useful in getting a system up and running without any hardware dependencies.