30 lines
1.1 KiB
Markdown
30 lines
1.1 KiB
Markdown
All Secure Digital (SD) storage devices contain one or two NAND flash memory chips and a processing unit to manage the operation of the card.
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There are three sizes of SD Card permitted by the spcification:
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1. original : 1.26 x 0.94 x 0.083 to 0.055 inches
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2. miniSD : 0.85 x 0.79 x 0.055 inches
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3. microSD : 0.56 x 0.43 x 0.039 inches
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or, in metric:
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1. original : 32 x 24 x 2.1-1.4 mm
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2. miniSD : 21.5 x 20 x 1.4 mm
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3. microSD : 15 x 11 x 1 mm
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Standard SD cards must have with a toggle switch that that permits or blocks write operations on the card.
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The mini and micro sized cards don't offer this feature.
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SD cards are available in five storage capacities:
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1. Standard (SDSC): up to 2 GB
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2. High (SDHC): from 2 to 32 GB
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3. Extended (SDXC): from 32 GB to 2 TB
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4. Ultra (SDUC): from 2 TB to 128 TB
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5. Input Output (SDIO): storage with a Bluetooth transciever and/or a GPS receiver
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# Storage Formats
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* SDSC FAT12, FAT16, and FAT16B.
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* SDHC FAT32
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* XC/HC exFAT
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The exFAT file format was specifically designed for NAND flash devices and is likely to remain the standard for many more years.
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