MultiMedia Card uses a 7-Pin connector [1 rows of 7 pins]. The 7-pin
connector is on 2.5-mil centers. The seven pin interface consists of
three pins dedicated to the SPI serial bus [SCK, SI, and SO], a Chip
Select signal [CS], a Chip Reset [RESET], a Write Protect line [WP], and
an output Ready/Busy [RDY/Busy] signal. All of the control signals except
the RDY signal are active low. The SPI interface uses the Serial Clock
[SCK] line, Serial Input [SI], and the Serial Output [SO] line. How ever
the physical DataFlash card does not have all the signals listed above,
refer to the pinout table shown below. A few of the signals listed above
may only be found on the DataFlash Integrated Circuits [ICs]. A smaller
form factor of MMC is called Reduced Size MultiMedia Card [RS-MMC]. The
RS-MMC card is 24mm x 16mm x 1.5mm. The RSMMC remains pin compatible with
the MMC module, but shorter
The newer versions of the standard; MMCplus, MMCmobile and MMCmicro, offer the higher transfer speeds up to 52MB/sec, or 416 Mbits/sec, and support for dual-voltage operation (1.8 and 3/3.3V), and multiple bus widths (x1, x4 and x8 bit). MMCplus, MMCmobile and MMCmicro utilize 13 pins while remaining backwards compatible with the previous version of 7-pin MMC cards.
The MultiMedia card dimensions are: 1.4mm thick x 24mm wide x 32mm long.
The 7-pin cards are form factor compatible with the DataFlash Card standard, and pin out compatible to the SPI version of the MMC card.
A short description of the SPI interface is listed on the Integrated Circuit Buses
|Pin #||Pin Name||Signal Function|
|2||SI||Serial Input [SPI]|
|4||Vcc||Voltage Supply [2.7v or 3.6v]|
|5||SCK||Serial Clock [SPI]|
|7||SO||Serial Output [SPI]|
Refer to this page for a list of different Flash Memory Stick Formats.