USB海量存儲(chǔ)設(shè)備類規(guī)范包括四個(gè)獨(dú)立的子類規(guī)范：(ATA command的那個(gè)沒(méi)有)
①USB Mass Storgage Class Control/Bulk/Interrupt(CBI)Transport
②USB Mass Storage Class Bulk-Only Transport
③USB Mass Storage Class ATA Command Block
④USB Mass Stroage Class UFI Command Specification。
前兩個(gè)子規(guī)范定義了數(shù)據(jù)/命令/狀態(tài)在USB上的傳輸方法。
Bulk-Only傳輸規(guī)范僅僅使用Bulk端點(diǎn)傳送數(shù)據(jù)/命令/狀態(tài)，
CBI傳輸規(guī)范則使用Control/Bulk/Interrupt三種類型的端點(diǎn)進(jìn)行數(shù)據(jù)/命令/狀態(tài)傳送。
后兩個(gè)子規(guī)范定義了對(duì)存儲(chǔ)介質(zhì)的操作命令。
ATA 命令規(guī)范用于硬盤。
UFI命令規(guī)范是針對(duì)USB移動(dòng)存儲(chǔ)而制定的，實(shí)際上UFI命令格式是基于SFF-8070i和SCSI-2規(guī)范，總共定義了19個(gè)12字節(jié)長(zhǎng)度的操作命令。
用AVR單片機(jī)設(shè)計(jì)的MP3播放器
功能：
MP3 Player
IDE ATA interface
FAT 32 with long file name support
USB interface
On board power supply (input from 7v to 20v DC)
Bootloader firmware upgradeable via USB port
Infrared bi-directional interface
Remote Control
Back light graphic LCD
worked with only 2x AA batteries
In sleep mode sink less than 1uA (2.5mA in active mode)
5 buttons for easy navigation
Long range (more than 20 feets)
