User guide

LSI Corporation
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12Gb/s MegaRAID SAS RAID Controllers User Guide
October 2013
Chapter 1: Overview
Configuration Scenarios
 High-end external SAS/SATA configuration: This configuration is for external connectivity using SATA II drives,
SATA III drives, SAS drives, or combinations of SATA and SAS drives. External enclosure management is supported
through in-band, SCSI-enclosed storage. The configuration must support STP and SMP.
The following figure shows a direct-connect configuration. The Inter-IC (I
2
C) interface communicates with peripherals.
The external memory bus provides an 8-bit/16-bit interface for connecting peripheral devices, such as nonvolatile
static random access memory (NVSRAM) and Flash ROM.
Figure 1 Example of an LSI SAS Direct-Connect Application
The following figure shows an example of a SAS RAID controller configured with an LSISASx12 expander that is
connected to SAS drives, SATA III drives, or both.
Figure 2 Example of an LSI SAS RAID Controller Configured with an LSISASx12 Expander
SAS
PCI Express
RAID Controller
SAS/SATA III Device
I
2
C
SAS/SATA III Device
SAS/SATA III Device
SAS/SATA III Device
PCI Express Interface
I
2
C
Interface
NVSRAM
Flash ROM/
Peripheral Bus
LSISASx12
Flash ROM/
NVSRAM/
SRAM
I
2
C/UART
LSISASx12
PCI Express Interface
8
SRAM
SRAMSDRAM
Peripheral
Bus
72-bit DDR3
with ECC
Interface
LSISAS3108
PCI Express to SAS ROC
SAS
RAID Controller
Expander
Expander