Universal Flash Storage (UFS)

UFS Version 2.1

UFS is specifically tailored for mobile applications and computing systems requiring high performance and low power consumption. In March 2016, JEDEC published JESD220C UFS 2.1, which is an update to version 2.0 (published in 2013). JESD220C Universal Flash Storage version 2.1 offers key improvements over earlier versions and will provide data security through the use of inline cryptography between the SoC and UFS Storage device. The new standard is available for free download from the JEDEC website.

Simplifying Design, Reducing System Cost & Improving Device Performance

JEDEC has also published four complementary standards; all are available for free download:

  • JESD223C UFS Host Controller Interface (UFSHCI) version 2.1
  • JESD220-1A UFS Unified Memory Extension version 1.1
  • JESD223-1A UFS Host Controller Interface, supporting Unified Memory Extension version 1.1
  • JESD224 UFS (Test)

JESD223C is intended to simplify the design process by defining a standard host controller interface on which system designers can create a common host controller software driver layer to work with UFS host controller hardware from different manufacturers.

JESD220-1A and JESD223-1A define enhancements needed in the UFS device and host controller to support Unified Memory Extension (UME) such as register definitions, protocol extensions and the capability to initiate transactions from UFS device side. The intent of UME is to share system memory with the UFS device, which allows a vast improvement of random access performance while offering potential to reduce system cost by minimizing the amount of UFS device internal working memory.

JESD224 defines standard test cases and procedures for measuring the behavior of UFS devices and comparing that with the requirements of the UFS standard.

UFS Card Standard

JESD220-2 Universal Flash Storage (UFS) Card Extension Standard was published in March 2016. The new removable memory card standard standardizes functionality that aligns with UFS version 2.0, JESD220B. JESD220-2 is available for free download from the JEDEC website.  Read more about JESD220-2.

Collaboration with the MIPI Alliance®

To achieve the highest performance and most power efficient data transport, JEDEC UFS aligns with industry–leading specifications from the MIPI Alliance to form its Interconnect Layer. This collaboration continues with UFS v2.1, which supports the M-PHY® Version 3.0 specification and the UniProSM Version 1.6 specification.

For more information about MIPI specifications related to UFS, visit: https://www.mipi.org/mipi-jedec/DocumentRequestWelcome.

About UFS

First published in February 2011, UFS is designed to be the most advanced standard for both embedded and removable Flash memory-based storage in mobile devices such as smartphones and tablets. UFS offers a low active power level and a near-zero idle power level, which, combined with the power-saving attributes of the related MIPI specifications, allows for significant reductions in device power consumption. The UFS standard adopts the well-known SCSI Architecture Model and command protocols supporting multiple commands with command queuing features and enabling a multi-thread programming paradigm. This differs from conventional Flash-based memory cards and embedded Flash solutions which process one command at a time, limiting random read/write access performance. The UFS HCI specification and the adoption of SCSI provide a well-known software programming model and are enabling wider market adoption. 

Work on UFS is coordinated by JEDEC's JC-64 Committee for Embedded Memory Storage and Removable Memory Cards, and is supported by principal consumer electronic and cell phone OEMs. In addition to UFS development work within JEDEC, some major participants have founded an organization, the Universal Flash Storage Association (UFSA), to develop an UFS ecosystem and support environment for UFS devices and host applications.