JEDEC publishes eMMC 4.5 standard

JEDEC Solid State Technology Association, the global leader in standards development for the microelectronics industry, today announced the publication of JESD84-B45: Embedded MultiMediaCard (eŸMMC), Electrical Standard (Version 4.5 Device). Continuing the evolution of e•MMC as an industry-leading memory standard for embedded non-volatile storage of system code, software applications and user data, the new e•MMC v4.5 standard defines functionality that focuses on improving the interaction between the host processor and the memory device at the interface, configuration and protocol levels, resulting in potential gains in overall system performance and reliability. JESD84-B45 is available for free download at http://www.jedec.org/standards-documents/results/jesd84-b45 .

eŸMMC v4.5 offers performance enhancement features, including an interface bandwidth increase from 104 Mbyte/sec to 200 MByte/sec. The command protocol is significantly improved with Packed Commands (the ability to group a series of commands in a single data transaction), Context ID (grouping different memory transactions under a single ID so the device can understand that they are related), and Data Tag (tagging specific write transactions so they can be prioritized and targeted to a memory region with higher performance and better reliability). The v4.5 standard also adds provision for volatile data cache, which can greatly reduce the latency between data transactions to improve performance.

Reliability enhancements include Power-Off Notification, which makes possible a more robust and safer power-down routine; as well as Dynamic Device Capacity, which provides a mechanism to increase device life time when the e•MMC device has reached its end-of-life, giving the user an opportunity to retrieve critical data from the device before disposal. The standard also adds the capability for the device to retrieve Real-Time Clock information from the host system, which may be used by the device internal memory management to improve data integrity and reliability.

In addition, e•MMC v4.5 provides features to better meet the requirements of the end applications, including enhanced partition attributes for system code and temporary data and separate data removal mechanisms. All performance and reliability enhancements offer designers additional options to improve system performance for the end user.

e•MMC v4.5 continues to support the current e•MMC ballout and adds a second e2MMC ballout that supports the Cache feature and 3 VDDi pins, which support an auxiliary storage medium (DRAM, Phase Change Memory, etc.) in the same device package. This enables manufacturers to fine-tune products by applying the best memory technology for a particular functionality and performance requirement.

“As mobile devices continue to require support for improved performance and reliability, JEDEC is pleased to help address the storage demands of the market with eŸMMC: a low-cost, high-performance solution,” said Mian Quddus, Chairman, JEDEC Board of Directors.