MMC (multimedia? Card) is the standard of flash memory card. 1997 was jointly developed by Siemens and SanDisk***. This technology is based on Toshiba's NAND flash memory technology, so it is smaller than earlier memory cards (such as CF cards) based on Intel NOR flash memory technology. The MMC card is about the size of a stamp, about 24 24 mm x 32 mm x1.5 mm. ..

MMC memory cards can be divided into two working modes: MMC and SPI. MMC mode is the standard default mode and has all the characteristics of MMC. SPI mode is the second mode that MMC memory cards can choose. This mode is a subset of MMC protocol, which is mainly used in systems that only need a few cards and have low data transmission rate. This mode can minimize the design cost, but the performance is not as good as MMC.

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The difference between MMC and SD card:

1, different institutions

SD card specifications are owned by organizations led by Panasonic, Toshiba and Sandisk.

The MMC specification is controlled by MMCA (Multimedia Card Association), which is led by a wide range of industry organizations.

2. Different slots

MMC card can be inserted into the physical slot designed for SD card, and there are two forms: thin and standard. Thin SD card can be inserted into MMC slot, but standard SD card can't be inserted because of thickness problem.

3. The number of pins is different.

The pin arrangement of MMC and SD card is compatible. SD card has at most 9 pins and MMC card has at most 13 pins.

References:

Baidu Encyclopedia-Multimedia Card

References:

Baidu Encyclopedia -—MMC