Hot Plug Support
PLX Technology, Inc.
Table 9-5. Hot Plug Board Removal Process
Operator / Action
Hot Plug Controller
Software
A. Presses Attention
1. Sets Attention Button Pressed bit to 1.
Button.
2. Generates Interrupt message due to Attention
Button pressed, if enabled.
Clears Attention Button Pressed bit to 0.
3. Transmits Interrupt de-assertion message,
if enabled.
Writes to the Slot Control register Power
Indicator Control field, to blink the Power
Indicator LED, which indicates that
the board is being powered down.
B. Power Indicator blinks. 4. Sets Power Indicator Control field to 10b.
5. Power Indicator Blink message is transmitted
to the downstream device.
6. Sets Command Completed bit to 1.
7. Generates Interrupt message due to Power Indicator
Clears Command Completed bit to 0.
command completion, if enabled.
8. Transmits Interrupt de-assertion message,
if enabled.
Sets Slot Control register Power Controller
Control bit to 1, to turn Off power to the
port.
C. Power Indicator Off.
9. Slot is powered Off.
Clears Command Completed bit to 0.
10. After a T
delay, sets the Command Completed
pepv
bit to 1.
Clears Power Indicator Control field to 00b,
to turn Off the Power Indicator LED, which
indicates that the slot is fully powered Off
and the board can be removed.
11. Generates Interrupt message due to Power Turn Off
command completion, if enabled.
D. Power Indicator Off,
board ready to be
removed.
12. Clears Power Indicator Control field to 00b.
13. Sets Command Completed bit to 1, due to Power
Indicator Off command completion.
Clears Command Completed bit to 0.
Clears MRL Sensor Changed bit to 0.
14. Transmits Interrupt de-assertion message,
if enabled.
E. Unlocks MRL.
15. Sets MRL Sensor State bit to 1.
16. Sets MRL Sensor Changed bit to 1.
17. Generates Interrupt message due to MRL Sensor
state change, if enabled.
18. Transmits Interrupt de-assertion message,
if enabled.
F. Removes board
19. Clears Presence Detect State bit to 0.
20. Sets Presence Detect Changed bit to 1.
from slot.
21. Generates Interrupt message due to Presence Detect
Clears Presence Detect Changed bit to 0.
change, if enabled.
22. Transmits Interrupt de-assertion message,
if enabled.
132
ExpressLane PEX 8532AA/BA/BB/BC 8-Port/32-Lane Versatile PCI Express Switch Data Book
Copyright © 2007 by PLX Technology, Inc. All Rights Reserved – Version 1.6
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