2-2
SAS-846A Backplane User's Guide
2-2 Front Connector and Pin Definitions
1. MG9072 Chip
The MG9072 is an enclosure management
chip that supports the SES-2 controller and
SES-2 protocols.
2. Upgrade Connectors
The upgrade connectors are designated JP69,
JP78, and JP115 and are used for manufactur-
er's diagnostic purposes only.
3. Activity LED Header
The activity LED header, designated JP26,
JP47 and JP108, is used to indicate the activ-
ity status of each SAS drive. The Activity LED
Header is located on the front panel. For the
Activity LED Header to work properly, connect
using a 10-pin LED cable.
4./5./6. I
2
C Connectors
The I
2
C Connectors, designated JP37, JP95,
JP52, JP96, JP116, and JP117, are used to
monitor HDD activity and status. See the table
on the right for pin definitions.
I
2
C Connector
Pin Definitions
(JP37, JP95, JP52, JP96,
JP116, and JP117)
Pin# Definition
1
Data
2
Ground
3
Clock
4
No Connection
Backplane
Main Power
4-Pin Connector
(JP10, JP13, JP46,
JP48, 109 and 110)
Pin# Definition
1
+12V
2 and 3
Ground
4
+5V
7. Backplane Main Power Connectors
The 4-pin connectors, designated JP10, JP13,
JP46, JP48, JP109, and JP110, provide power
to the backplane. See the table on the right for
pin definitions.
