The
MultiMediaCard

System Summary
MMCA Technical Committee
Based on System Specification Version 2.11

The MultiMediaCard is an universal low cost data storage and communication media. It is designed
to cover a wide area of applications as electronic toys, organizers, PDAs, cameras, smart phones,
digital recorders, pagers, etc. Targeted features are high mobility and high performance at a low
cost price. It might also be expressed in terms of low power consumption and high data throughput
at the memory card interface.
The MultiMediaCard communication is based on an advanced 7-pin serial bus designed to operate
in a low voltage range. The communication protocol is defined as a part of this standard and
referred to as MultiMediaCard mode. For compatibility to existing controllers cards may offer, in
addition to the MultiMediaCard mode, an alternate communication protocol which is based on the
SPI standard.
This document gives a general overview of the MultiMediaCard system architecture. A detailed
description can be found in “MultiMediaCard System Specification Version 2.11”, Official Release,
MMCA 1999.
The document is split up into several portions. Chapter 3 gives a general overview of the system
components - card, bus and host. In the next two chapters the card registers and the MultiMediaCard
bus are described. An introduction to the SPI mode is given in Chapter 6. The error protection
techniques employed in this standard are described in Chapter 7. For achieving high data
interchangeability, three basic file formats are introduced in Chapter 8 as valid file formats for the
MultiMediaCard. Finally, the standard compliance criteria for the cards and hosts are given in the
last chapter.