Mass Data Management for Embedded Systems: Compact Flash

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Mass Data Management for Embedded Systems
Compact Flash

• Eric Ng, MSME
• EE281 ESDL
• December 4, 2002

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Presentation Overview

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

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Reasons for Using Compact Flash

• PortableLow Power Data management has become
  crucial in todays 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 10ms10x faster than floppy
• Nonvolatile Memory 10 yr retention

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Other Mass Storage Options

• Sony Memory Stick
• IBM Microdrive
• MultiMedia Card (MMC) or Secure Digital Card
  (SD)
  
• SmartMedia Card (SMC)

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Introduction to UsingCompact 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

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Step 1 IDE to CF Adapter
http//www.acscontrol.com 19.99
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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)

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Step 3 Accessing the Registers
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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

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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)

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Resources

• CompactFlash Association
• http//www.compactflash.org
• Microsoft
• File Allocation Table (FAT) White Paper
• IDE to CF Adapter
• http//www.acscontrol.com

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Memory Comparison