The SAS expander device consists of 18 10-bit serializer/deserializers (SerDes), per-PHY

diagnostics facilities, retiming elasticity buffers, a target/initiator-capable SMP virtual PHY

engine, a target/initiator-capable STP virtual PHY engine, multiple I²C serial interfaces, a v3000

CPU, two UARTs, and a variety of general-purpose I/O (GPIO) including SGPIO. Each

receiver’s incoming data is monitored and checked for 8b/10b violations, data path parity errors,

disparity errors, CRC errors, and many other common error conditions.

The VSC7155 is a highly integrated solution that provides high-performance characteristics,

expander/enclosure management, as well as industry leading high-speed inputs/outputs that

can drive 3.0Gbps signals across existing backplanes.

Customers already using Maxim enclosure management controllers are able to reuse their

software from previous products for reduced time-to-market and development effort.

Key Features



18 SAS Expander PHYs with Integrated SerDes



Each PHY Can Operate Independently at 1.5Gbps or 3.0Gbps



Configurable as a SAS Fanout or Edge Expander



Nonblocking Switch Architecture (Any PHY to Any PHY Connectivity)



Table Routing (Up to 320 Destination Addresses)



SMP and SSP Virtual PHY with Initiator and Target Capability



Embedded Enclosure Management Processor (Stanford-1, 32-Bit RISC) for Local

Control and SES Functions



Four Operating Modes: Parallel Master, Parallel Slave, I²C Serial Interface Slave, and

SPI™ Master



Automatic PHY Speed Detection and Negotiation



Serial ATA Drive Support Using Internal STP/SATA Bridging Functions (1 per PHY)



Programmable Output Deemphasis and Input Signal Equalization Levels



Variable Wide-Port Support

Applications/Uses



Blade Servers



Disk-Based Backup Storage



Enterprise Storage Environments



Fabric Attached Storage (FAS) Systems



Fixed-Content Storage Systems



JBOD Arrays



Modular Direct-Attached Storage (DAS)



Near-Line Storage Replacement Systems



Network Attached Storage (NAS) Systems



Rack-Mounted Servers with RAID



Storage Area Network (SAN) Appliances