Multiplier Chips And Port Selector Implement Efficient SATA Interfaces

April 13, 2006
Also known as IDE, the Advanced Technology Attachment (ATA) standard has dominated data transfer to and from hard-disk drives for years. But as the need to address storage units far from the server grows and transfer speeds increase, this parallel ATA st

Also known as IDE, the Advanced Technology Attachment (ATA) standard has dominated data transfer to and from hard-disk drives for years. But as the need to address storage units far from the server grows and transfer speeds increase, this parallel ATA standard becomes unusable.

The Serial ATA (SATA) interface extends the range and speed of disk data transfer, solving these problems. Exar's Xstor port selector and multiplier chips make implementation of this interface fast and easy.

The Exar XRS10L140 is a 1:4 port multiplier for SATA II applications in enterprise-class disk-array systems. It includes the 1:4 port multiplier and a two-port selector for dual hosts—an industry first. Both support the 3- and 1.5-Gbit/s data rates with rate detection and speed negotiation features.

These devices address the challenges of interfacing with disk drives. For example, backplanes are getting faster and longer. Dual-ported drives need to be addressed. SATA wants to go outside the box. SATA drives are now in Fibre Channel systems for secondary storage. Failover systems are necessary for SATA-based arrays. SATA systems need external connectors. And, there's a need for simple disk-based backup systems.

The XRS10L140 port multiplier lets the SATA host server communicate with up to four SATA storage devices. It's designed to be part of the board that plugs into the PCI bus on the host or in a RAID controller box. The four ports to the drives may use up to 1 m of copper lines on an FR-4 PC board or up to 15 m of unequalized copper cable, usually coax.

The 3- and 1.5-Gbit/s speeds are attained by including a superior analog front end with selectable emphasis and equalization to extend the link budgets and improve signal integrity. A direct-sequence spread-spectrum clocking feature greatly reduces electromagnetic interference. The device fully complies with all recent SATA specifications.

Other features include multiple power-down modes, out of band (OOB) signaling, support for the MDIO bus and self test, an I2C interface, and a JTAG test port. Made with 0.13-µm CMOS, the device operates from a 1.2-V supply. It comes in a 100-pin quad-flat no-lead (QFN) package.

The XRS10L240 includes all the features of the XRS10L140 (see the figure). It also offers a two-port selector that enables the four storage devices to work with two different hosts. This permits implementation of a failover path from two independent hosts.

The port-selector function also is used when dual hosts such as I/O controllers must access single-port disk drives in high-availability storage subsystems where redundancy and load sharing are specified. The XRS10L240 uses the same 100-pin QFN package as well.

The XRS10L140 costs $8 and the XRS10L240 costs $25, both in 1000-unit quantities. Additional members of the Xstor family will be offered later this year.

Exar Corp.
www.exar.com

Sponsored Recommendations

Understanding Thermal Challenges in EV Charging Applications

March 28, 2024
As EVs emerge as the dominant mode of transportation, factors such as battery range and quicker charging rates will play pivotal roles in the global economy.

Board-Mount DC/DC Converters in Medical Applications

March 27, 2024
AC/DC or board-mount DC/DC converters provide power for medical devices. This article explains why isolation might be needed and which safety standards apply.

Use Rugged Multiband Antennas to Solve the Mobile Connectivity Challenge

March 27, 2024
Selecting and using antennas for mobile applications requires attention to electrical, mechanical, and environmental characteristics: TE modules can help.

Out-of-the-box Cellular and Wi-Fi connectivity with AWS IoT ExpressLink

March 27, 2024
This demo shows how to enroll LTE-M and Wi-Fi evaluation boards with AWS IoT Core, set up a Connected Health Solution as well as AWS AT commands and AWS IoT ExpressLink security...

Comments

To join the conversation, and become an exclusive member of Electronic Design, create an account today!