Intel 12Gb/s, Руководство пользователя

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4 12Gb/s Intel® RAID Controllers User Guide
The following figure shows a direct-connect configuration. The Inter-IC (I
2
C) 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 (PSBRAM), nonvolatile static random access memory (NVSRAM), and
Flash ROM.
Figure 1. Example of an Intel 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 Intel SAS RAID Controller Configured with an
LSISASx12 Expander
Benefits of the SAS Interface
SAS is a serial, point-to-point, enterprise-level device interface that leverages the proven
SCSI protocol set. SAS is a convergence of the advantages of SATA, SCSI, and Fibre
Channel, and it is the future mainstay of the enterprise and high-end workstation storage
markets. SAS offers a higher bandwidth per pin than parallel SCSI, and it improves signal
and data integrity.
Flash ROM/ SAS
PCI Express
RAID Controller
SAS/SATA III Device
32-Bit Memory
Address/Data
Bus
PSBRAM/
I
2
C
SAS/SATA III Device
SAS/SATA III Device
SAS/SATA III Device
PCI Express Interface
NVSRAM
I
2
C
Interface
LSISASx12
Flash ROM/
NVSRAM/
SRAM
I
2
C/UART
LSISASx12
PCI Express Interface
8
SRAM
SRAM SDRAM
Peripheral
Bus
72-bit DDR3
with ECC
Interface
LSISAS3108
PCI Express to SAS ROC
SAS RAID Controller
Expander Expander