Mass Data Management for Embedded Systems: Compact Flash Eric Ng, MSME EE281: ESDL December 4, 2002

Presentation Overview Reasons for using Compact Flash Other Mass Storage Options Step-by-Step Guide to using CF FAT (File Allocation Table) Overview

Reasons for Using Compact Flash Portable+Low Power: Data management has become crucial in today’s embedded systems. Data loggers, MP3 Players, Digital Cameras, PDAs No Mechanical Parts: withstands higher shock impacts compared to HDDs. ~1000Gs vs ~200Gs (Operating Condition) Relatively Inexpensive: 512MB ~ $120 Fast: avg seek time: 10ms;10x faster than floppy Nonvolatile Memory: 10 yr retention

Other Mass Storage Options Sony Memory Stick IBM Microdrive MultiMedia Card (MMC) or Secure Digital Card (SD) SmartMedia Card (SMC)

Introduction to Using Compact Flash Lots of literature, but straight forward. Compact Flash has HDD interface. PC AT Attachment (ATA) Its compact nature may be difficult to interface without adapter. IDE to Compact Flash Adapter Step-by-Step Guide >>

Step 1: IDE to CF Adapter

Step 2:  controller Interface CF has 50 pin outs, but requires only following connections Data Port (8-bit or 16-bit) Address Lines (5) Read/Write Lines (2)

Step 3: Accessing the Registers

Example: Reading Data Initialization Sequence: (1) Set Features to Enable 8-bit transfers (2) Enable Logical Block Addressing (LBA) Identify sector by writing to LBA registers Call command: Read Sectors Retrieve data from Data Register

Summary Compact Flash is EASY to use! (1) Get adapter (2) Interface with u-controller (3) Learn to use the registers File Organization in the CF File Allocation Table (FAT)

Resources CompactFlash Association Microsoft File Allocation Table (FAT) White Paper IDE to CF Adapter

Memory Comparison