Product manual
3.4 Compact Flash Card
#& CARDS WERE lRST DEVELOPED IN BY 3AN$ISK 4HESE ARE THE CARDS OFFERING THE HIGHEST
CAPACITIES FROM -" TO '" 4ODAY #& CARDS ARE USED IN EXPENSIVE PROFESSIONAL DIGITAL
CAMERAS AND OTHER PROFESSIONAL MASS STORAGE DEVICES ,OWCAPACITY CARDS UP TO '" USE
THE &!4 lLING SYSTEM AND CARDS WITH CAPACITIES HIGHER THAN '" USE THE &!4 lLING
SYSTEM
4HERE ARE TWO VERSIONS OF #& CARDS 4YPE ) AND 4YPE )) 4HE ONLY PHYSICAL DIFFERENCE BETWEEN
THE TWO TYPES IS THAT 4YPE )) CARDS ARE THICKER THAN 4YPE ) CARDS 4YPE ) CARD DIMENSIONS ARE
s s MM AND 4YPE )) CARDS ARE s s MM "OTH CARDS HAVE PINS
4HE 4YPE ) INTERFACE CAN SUPPLY UP TO M! TO THE CARD AND THE 4YPE )) INTERFACE CAN SUPPLY
UP TO M! 4HE CARD OPERATING VOLTAGE IS OR 6 &IGURE SHOWS A TYPICAL #& CARD
4HERE ARE FOUR SPEEDS OF #& CARDS A 3TANDARD #& A #& (IGH 3PEED #& WITH A DATA
TRANSFER RATE OF -"S A FASTER #& WITH A DATA TRANSFER RATE OF -"S AND THE FASTEST
#& STANDARD WITH A DATA TRANSFER RATE OF -"S ! FUTURE VERSION OF THE #& CARDS
KNOWN AS #&AST WILL BE BASED ON THE 3ERIAL !4! BUS WITH AN EXPECTED SPEED OF -"S
4HE MEMORY CARD SPEED IS USUALLY SPECIlED USING THE hXv RATING 4HIS IS THE SPEED OF THE lRST
AUDIO #$2/- WHICH WAS +"S &OR EXAMPLE A CARD WITH A SPEED OF X CORRESPONDS
TO A DATA TRANSFER RATE OF s +"S -"S 4ABLE LISTS SOME OF THE COMMONLY
USED SPEED RATINGS IN MEMORY CARDS
4HE ADVANTAGES OF #& CARDS ARE AS FOLLOWS
#& CARDS ARE RUGGED AND MORE DURABLE THAN OTHER TYPES OF CARDS AND THEY CAN WITHSTAND s
MORE PHYSICAL DAMAGE THAN OTHER CARDS
#& CARDS ARE AVAILABLE AT VERY HIGH STORAGE CAPACITIES s
#& CARDS OPERATE AT HIGH SPEEDS s
#& CARDS ARE COMPATIBLE WITH THE )$%!4! HARDDISK STANDARDS AND THUS THEY CAN BE s
USED IN MANY EMBEDDED SYSTEMS TO REPLACE HARD DISKS
"ESIDES THE ADVANTAGES THE #& CARDS HAVE SOME DISADVANTAGES SUCH AS LACK OF A MECHANICAL
WRITE PROTECTION SWITCH OR NOTCH AND ITS LARGE DIMENSIONS IN COMPARISON WITH OTHER CARDS
LIMIT ITS USE IN SLIM DEVICES
Figure 3.3: Compact Flash Card
110 Chapter 3
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