Power Management
PLX Technology, Inc.
Table 10-2. Supported PCI Express Power Management Capabilities (Cont.)
Register
Supported
Description
Offset
Bit(s)
Yes
No
Slot Status and Control (for Downstream Ports)
Power Fault Detector Enable
0 = Function is disabled
1 = Enables software notification with a Hot Plug interrupt if the port is in the D0
Power State (Power Management Status and Control register Power State field,
offset 44h[1:0]=00b), or with a PME message if the port is in the D3hot state
(offset 44h[1:0]=11b), for a Power Fault event on the corresponding PEX 8532
downstream port.
✔
1
Do not change for upstream port.
Power Indicator Control
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
11b = Turns Off indicator
✔
9:8
Software must use a Byte or Word Write (and not a DWord Write) to control the
HP_PWRLEDx# Output signal.
80h
Reads return the corresponding PEX 8532 downstream port Power Indicator’s
current state.
Do not change for upstream port.
Power Controller Control
Controls the Power Controller on the corresponding PEX 8532 downstream port slot.
0 = Turns On Power Controller; requires some delay to be effective
1 = Turns Off Power Controller
✔
10
17
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.
Power Fault Detected
Set to 1 when the Power Controller of the corresponding PEX 8532 downstream port
slot detects a Power Fault at the slot.
✔
Do not change for upstream port.
Power Budgeting Extended Capability
Extended Capability ID
15:0
✔
✔
Set to 0004h, as required by the PCI Express Base r1.0a.
Capability Version
138h
19:16
Set to 1h, as required by the PCI Express Base r1.0a.
Next Capability Offset
31:20
✔
Set to 148h, which addresses the PEX 8532 Virtual Channel Extended Capability
registers.
Data Select
Data Select
Indexes the Power Budgeting Data reported by way of eight Power Budgeting Data
registers per port and selects the DWord of Power Budgeting Data that appears in each
Power Budgeting Data register. Index values start at 0, to select the first DWord of
Power Budgeting Data; subsequent DWords of Power Budgeting Data are selected
by increasing index values 1 to 7.
13Ch
✔
7:0
142
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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