MMC protocol helps memory cards communicate with a mobile phone.
Flash memory in memory cards offers advantages in endurance and power use, compared with other types of memory. Memory cards that have flash memory communicate with a host device, such as a mobile phone, using protocols such as the MMC (multimedia card) protocol and SPI (serial peripheral interface) protocol. These protocols help make for effective communication.
Communication
A protocol is a language that allows different devices to communicate with each other by sending signals. For a protocol to be executed, data has to be saved into the memory card through a write process. A read process then reads the data from the device. Both these processes have to be executed without error for the communication protocol to be successful.
MMC Protocol
The MMC protocol was initially set up to read and write data contained in a flash memory. It is also used to exchange data and communicate with smart cards. MMC memory cards that smart phones use can communicate with smart cards using this protocol. However, a USB interface has become more of the standardized format for smart card interfaces.
Requirements
The MMC protocol uses a minimum of three electrical connections. One connection serves as a clock line, another in order to command and a third that serves as a data path. With the right setup of these lines, the MMC protocol helps transfer the data in parallel, given that it is a synchronous protocol. The highest data transmission rate with these three connections is 416 Mbits.
SPI Protocol
The Multimedia Card interface puts into effect the MMC protocol using either a standard format or as SPI protocol. Although the two formats are similar, they differ in one respect. The standard MMC format uses two lines, with one taking in data and another one to issue commands. The SPI protocol exchanges commands and data using one line for input and another for output. MMC interface provides a choice in terms of choosing the standard format or the SPI protocol.
Tags: communicate with, memory cards, standard format, cards that, communicate with smart, flash memory
