How Secure Digital Memory Cards Work

The Future for Secure Digital Cards

Some laptops feature SD card readers, making it quick and easy to read SD cards from cameras and other devices.
Some laptops feature SD card readers, making it quick and easy to read SD cards from cameras and other devices.
Photo by Stephanie Crawford

With the boom in SD card technology in thousands of devices, it's natural to conclude that SD cards will be around for years to come. The SD Association continues to expand on SD cards, incorporating new standards as manufacturers contribute improvements to flash-memory technology. As of this writing, the UHS-II was in development to standardize even faster read-write speeds for SD cards.

With so many devices adding SD card readers, manufacturers have asked, "Can you use that slot for other things besides flash memory?" The hardware interface provides both power and data exchange for SD cards, so it seems reasonable to assume that it could do more than just read and write data. Recognizing this demand, the SD Association developed the SDIO card interface. By adding an SDIO card interface to a device, manufacturers can adapt the device for use in an existing SD card reader.

Here are just some of the functionalities covered by the SDIO card interface standard:

  • Wireless connectivity using 802.11b Wi-Fi or Bluetooth
  • Media capture through cameras and voice recorders
  • Scanners and barcode readers
  • TV and radio tuners

One amazing little device taking advantage of SDIO is the Eye-Fi card. Founded in 2005, Eye-Fi, Inc. has patent-pending technology that can turn the SD card slot in your camera into a portal for uploading photos directly to the Web. The Eye-Fi card includes a Wi-Fi radio and software designed to connect to a Wi-Fi network, and then use that connection to upload photos to your computer or a photo-sharing Web site like Flickr or Facebook. Eye-Fi cards range from $49.99 to $99.99.

In short, the future for SD cards looks bright thanks to the wide adoption of SD standards and the continued improvements and expansions to those standards. In addition, the cost of SD cards seems to be more reasonable over time, with brand competition keeping prices in check. For more information on Secure Digital memory cards, plug in to the next page.

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More Great Links


  • 4C Entity, LLC. "About Us." (Sept. 27, 2011)
  • 4C Entity, LLC. "FAQs." (Sept. 27, 2011)
  • Eye-Fi, Inc. "About Us." (Sept. 28, 2011)
  • Intel Corporation. "Intel and CPRM/CPPM." (Sept. 27, 2011)
  • SD Association. "Copyright Protection." (Sept. 27, 2011)
  • SD Association. "Fact Sheet." (Sept. 27, 2011)
  • SD Association. "Frequently Asked Questions." (Sept. 27, 2011)
  • SD Association. "Greater Performance Choices." (Sept. 27, 2011)
  • SD Association. "Developers Overview." (Sept. 27, 2011)
  • SD Association. "SDIO." (Sept. 27, 2011)
  • Toshiba. "Toshiba America Electronic Components, Inc. Releases Performance Research on MLC NAND Flash Memory For Consumer Applications." May 20, 2004. (Sept. 27, 2011)