14. Register Descriptions > PCI Capability Registers
164
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
14.5.5
PCI Power Management Control and Status Register
This register defines the control and status registers of the power management capability option.
Register name: PCI_PMCS
Reset value: 0x0000_0008
Register offset: 0x0A4
Bits
7
6
5
4
3
2
1
0
31:24
DATA
23:16
BPCCE
B2B3S
Reserved
15:08
PME_ST
DATA_SC
DATA_SEL
PME_EN
07:00
Reserved
NO_SOFT_
RST
Reserved
PWR_ST
Bits
Name
Description
Type
Reset value
31:24
DATA
Power Data
The PEB383 does not support the Power Data field.
R
0x00
23
BPCCE
BPCC_En (Bus Power/Clock Control Enable) - A “1”
indicates that the bus power/clock control mechanism as
defined in Section 4.7.1 is enabled.
A “0” indicates that the bus power/clock control policies
defined in Section 4.7.1 have been disabled.
When the Bus Power/Clock Control mechanism is disabled,
the bridge’s PMCSR PowerState field cannot be used by the
system software to control the power or clock of the bridge’s
secondary bus.
This bit will be set if “PCGE” is set in
, and the PCI_CLK is 33MHz or less.
R
0x0
22
B2B3S
B2_B3# (B2/B3 support for D3hot) - The state of this bit
determines the action that is to occur as a direct result of
programming the function to D3hot.
A “1” indicates that when the bridge function is programmed
to D3hot, its secondary bus’s PCI clock will be stopped (B2).
A “0” indicates that when the bridge function is programmed
to D3hot, its secondary bus will have its power removed
(B3).
This bit is only meaningful if bit 7 (BPCC_En) is a “1”.
This bit will be set if “PCGE” is set in
, and the PCI_CLK is 33MHz or less.
R
0x0
21:16
Reserved
Reserved. It always reads 0.
R
0x0