VSC7155

18-PHY 1.5Gbps and 3.0Gbps SAS Edge/Fanout

Expander with Table Routing and SSP Engine

Low-Cost Single-Chip SAS Edge/Fanout Expander

This product is Not Recommended for New Designs. Some versions may be No Longer

Available or being discontinued and subject to Last Time Buy, after which new orders can not

be placed.

Description

The VSC7155 is a multimode, user-configurable 18-PHY Serial Attached SCSI (SAS) expander.

The device provides SAS port expansion as defined by the ANSI T10 Serial Attached SCSI 1.0

and 1.1 specifications for both edge and fanout expanders. The VSC7155 is targeted at

embedded applications in the midrange and enterprise storage environments including blade

servers, JBODs, and RAID systems. It offers an attractive technology upgrade for those

systems that currently employ parallel SCSI technology and have substantial reliance on SCSI-

centric applications software or management solutions.

The VSC7155 provides active port expansion for up to 18 connected PHYs with connections

made via a high-performance internal nonblocking cross-bar matrix.

Programmable output preemphasis and input signal equalization ensure consistent high signal

quality in lengthy in-and-out-of-box backplanes or cable infrastructures.

The on-board CPU in the VSC7155 performs the role of an SMP management application client

and can participate in enclosure management functions through serial I²C interfaces, an

embedded Ethernet controller, or vendor-specific SMP implementations.

The VSC7155 is a SAS expander containing all the functions needed to implement a 1.5Gbps

or 3.0Gbps SAS enterprise server or JBOD system. This device is typically used in distributing

SAS signals to an array of disk drives either in a server or an external enclosure. Commonly,

two or more “initiator” ports connect to the SAS SCSI SAN and several disk ports connect to

drives over a 3Gbps serial backplane. The embedded enclosure management controller,

software/firmware-compatible with other Maxim enclosure management controllers, configures

and monitors both the VSC7155 and the entire enclosure through flexible low-speed interfaces.