Nonvolatile Flash Memory Storage

5/10/2007

Flash semiconductor memory can be configured to serve as the mass storage device for a computer. Because there is no mechanical track seek and rotational delay, read access time can be superior to a hard disk drive. Also, form factor is typically smaller and power consumption is usually lower than a mechanical drive.

If you want to allow the flash device to behave as a typical writable storage device, you may need a custom file system implementation to accommodate the flash memory page erase characteristics.

The following table shows some flash form factors that you can use in your device.

Flash form factor Description

Single chip flash disk

Memory packaged into one chip that can be installed on a computer motherboard.

Flash drive SCSI / IDE

Linear flash memory packaged with a SCSI or IDE controller to emulate a SCSI or IDE hard disk drive.

Type I/II PCMCIA flash cards

Linear flash memory packaged into PC Cards that emulate a PCMCIA ATA device.

CompactFlash device

Smaller than a PC Card with electrically compatible connector interface. Removable, and provides PCMCIA-ATA and TrueIDE functionality that is compatible with ATA/ATAPI-4.

For more information, see CompactFlash.

MultiMediaCard

A stamp size flash device that resides on a MultiMediaCardserial bus. Typically nonbootable.

MemoryStick

A Sony high-density flash memory device that resides on a serial bus. Typically nonbootable.

Windows XP supports the devices in the table that emulate a disk using SCSI or IDE interface through an ATA or SCSI driver.

Be aware of the following considerations before deploying to nonvolatile flash:

  • You can write-protect your device by using the Enhanced Write Filter (EWF) component.
  • You can use the MultiMediaCard and MemoryStick as system storage, or to deploy your run-time image to a device.

See Also

Concepts

Volatile and Nonvolatile Storage Devices