14. Register Descriptions > PCIe Capability Registers
183
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
6
COM_CLK
PCIe Common Clock Configuration
This field selects between a distributed common reference
clock or an asynchronous reference clock. After setting both
ends of the link to the same value, the link must be retrained
from the bridge side of the link.
Components use this common clock configuration
information to report the correct L0s and L1 Exit Latencies.
0 = Asynchronous reference clock
1 = Distributed common reference clock
R/W
0
5
RETRAIN
PCIe Retrain Link
This field is reserved for a bridge device. It always reads 0.
R
0
4
LNK_DIS
PCIe Link Disable
This field is reserved for a bridge device. It always reads 0.
R
0
3
RCB
PCIe Read Completion Boundary
This field is set by system software to indicate the read
completion boundary value of the upstream root port.
0 = 64 bytes
1 = 128 bytes
R/W
0
2
Reserved
PCIe Reserved. It always reads 0.
R
0
1:0
ASPM_CTL
PCIe ASPM Control
This field enables different levels of ASPM.
00: Disabled
01 :L0s Entry enabled
10: L1 entry enabled
11: L0s and L1 entry enabled
R/W
00
(Continued)
Bits
Name
Description
Type
Reset value