LSI 25083 1.4 Configuration Scenarios

1-6 Overview

•3Gb/s SATA II

•Staggered spin-up

•Hot plug

•Native command queuing

•Activity and fault indicators for each PHY

•Port selector (for dual-port drives)

Each port on the SAS controllers supports SAS devices, SATA II devices,

or both using SSP, SMP, STP, and SATA II. SSP enables communication

with other SAS devices. SATA II enables the SAS controllers to

communicate with other SATA II devices.

1.4 Configuration Scenarios

There are three main scenarios in which you can use the SAS RAID

controllers:

•Low-end, internal SATA II configurations: In this configuration, use

the RAID controller as a high-end SATA II compatible controller that

connects up to eight drives either directly or through a port expander.

This configuration is mostly for low-end or entry servers. Enclosure

management is provided through out-of-band I2C bus. Side bands of

both types of internal SAS connectors support the SFF-8485

(SGPIO) interface.

•Midrange internal SAS configurations: This is like the internal

SATA II configurations, but with high-end SAS drives. This is more

suitable for low-range to midrange servers.

•High-end external SAS/SATA II configurations: This configuration

is for external connectivity using SATA II drives, SAS drives, or both.

External enclosure management is supported through in-band,

SCSI-enclosed storage. The configuration must support STP and

SMP.

Figure 1.1 shows a direct-connect configuration. The Inter-IC (I2C)

interface communicates with peripherals. The external memory bus

provides a 32-bit memory bus, parity checking, and chip select signals

for pipelined synchronous burst static random access memory