February, 2007
PCI Express Capability Registers
Register 11-29. 80h Slot Status and Control (All Ports) (Cont.)
Serial
Bit(s)
Description
Power Indicator Control
Ports
Type
Default
EEPROM
Upstream
RO
No
00b
Do not change for upstream port.
Controls the Power Indicator on the corresponding
PEX 8532 downstream port slot.
00b = Reserved – Writes are ignored
01b = Turns On indicator to constant On state
10b = Causes indicator to blink
9:8
11b (MRL open)
01b (MRL closed)
11b = Turns Off indicator
Downstream
RW
Yes
Software must use a Byte or Word Write (and not
a DWord Write) to control the HP_PWRLEDx#
Output signal.
Reads return the corresponding PEX 8532
downstream port Power Indicator’s current state.
Power Controller Control
Upstream
RO
No
0
Not valid for the upstream port.
Controls the Power Controller on the corresponding
PEX 8532 downstream port slot.
0 = Turns On Power Controller; requires some delay
to be effective
10
1 (MRL open)
0 (MRL closed)
1 = Turns Off Power Controller
Downstream
RW
Yes
Software must use a Byte or Word Write (and not
a DWord Write) to control the Power Controller
Output signals.
Note: Value of 0 requires some delay to be effective.
15:11 Reserved
0-0h
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
187
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