MultiMediaCard

MultiMediaCard

32 MB MMCplus card
Media type	Memory card
Capacity	Up to 512 GB
Developed by	JEDEC
Dimensions	Standard: 32 × 24 × 1.4 mm
Weight	Standard: ~2.0 g
Usage	Portable devices
Extended to	Secure Digital (SD)
Released	1997

MultiMediaCard, officially abbreviated as MMC, is a memory card standard used for solid-state storage. Unveiled in 1997 by SanDisk and Siemens,^[1] MMC is based on a surface-contact low-pin-count serial interface using a single memory stack substrate assembly, and is therefore much smaller than earlier systems based on high-pin-count parallel interfaces using traditional surface-mount assembly such as CompactFlash. Both products were initially introduced using SanDisk NOR-based flash technology.

MMC is about the size of a postage stamp: 32 mm × 24 mm × 1.4 mm. MMC originally used a 1-bit serial interface, but newer versions^[when?] of the specification allow transfers of 4 or 8 bits at a time. MMC can be used in many devices that can use Secure Digital (SD) cards. MMCs may be available in sizes up to 16 gigabytes (GB).

They are used in almost every context in which memory cards are used, like cellular phones, digital audio players, digital cameras, and PDAs. Typically, an MMC operates as a storage medium for devices, in a form that can easily be removed for access by a PC via a connected MMC reader.

eMMC (embedded MMC) is a small MMC chip used as embedded non-volatile memory that is normally soldered on printed circuit boards, though pluggable eMMC modules are used on some devices (e.g. Orange Pi and ODROID).^[2][3][4]