Intel SE8500HW4 - Manual (Page 36)

Intel® Server Board Set SE8500HW4 Memory Board Intel® Server Board Set SE8500HW4
Revision 1.0
Intel order number D22893-001
24
4.5.1 Button, Retention Latch and LEDs
The following sections provide an overview of the hardware required to support memory hot
plug. See Section 10.1 for more information about memory hot plug support on the Intel
®
Server
Board Set SE8500HW4.
4.5.1.1 Attention Button
This is a user accessible push button that initiates the proper shut down of the Memory Board
during a memory hot plug event. When pushed, a notification is sent to the memory hot plug
controller on the Mainboard. The system blinks the attention LED until the request can be
serviced. The BIOS interprets the request as a hot removal if the Memory Board is included in
the current system memory configuration or as a hot add if it is not.
If the system rejects the removal request, the power LED remains lit. A removal request may be
rejected if the current memory mode does not support hot removal. For example if only three
good boards in a memory RAID mode remain, the system will reject a removal request to any of
those three boards. If the system accepts the removal request it blinks the power LED, de-
initializes the board, then turns off the power LED. After the power LED is turned off, the user
may open the retention latch to remove the Memory Board.
4.5.1.2 Retention Latch
The retention latch is a mechanical lock and handle used to remove the Memory Board from a
chassis and the Mainboard. In the event of an unexpected memory hot plug operation, non-
accessible buttons under the retention latch will turn off power to the Memory Board. This safety
feature is included to protect the user and circuits in the event that the attention button was not
used properly.