Register Description
3.8.1.22
Offset 50h: LCAP—Link Capabilities Register (D0:F1, F3)
Offset:
Default Value: 0003E081h
50-53h
Attribute: RO
Size: 32 bits
This register identifies PCI Express* link specific capabilities of the Intel® 6700PXH 64-bit PCI
Hub.
Bits
Type
Reset
Description
31:24
RO
0
Port Number (PNUM): Not applicable to the Intel® 6700PXH 64-bit PCI Hub
and reserved to zero.
23:18
17:15
RO
RO
0
Reserved.
111b
L1 Exit Latency (L1XL): L1 transition is not supported by the Intel® 6700PXH
64-bit PCI Hub.
14:12
RO
6h
L0 Exit Latency (L0XL): L0s Exit Latency: The value in these bits is
influenced by the PCI reference clock configuration in the Intel® 6700PXH 64-
bit PCI Hub, since the reference clock is configured as a common clock.
Because it is a common clock configuration, the Common Clock Configuration
bit (CCC, bit 6) in the Link Control register (LCTL, offset 54h) is set to a 1. The
mapping is shown below:
Bit 6 PCI Express* Link Control Link Capabilities Bits 14:12
0
1
110b = 2-4 us.
010b - 128 ms to less than 256 ms
Note that software could write the bit 6 in link control register to either a 1 or 0,
and these bits should change accordingly.
11:10
RO
0
Active State Link PM Support (ASLPMS): Indicates the level of active state
power management supported on the given PCI Express* link. The PCI-SIG
defined encodings are as follows:
00 L0s entry disabled.
01 Intel® 6700PXH 64-bit PCI Hub enters L0s per the specified requirements
for L0s entry.
10 L0s entry disabled.
11 L0s entry disabled.
The Intel® 6700PXH 64-bit PCI Hub supports only L0s, so this field is set to
01h. Not used by I/OxAPIC in normal operation.
9:4
3:0
RO
RO
8h
Maximum Link Width (MLW): Intel® 6700PXH 64-bit PCI Hub supports a
maximum PCI Express* link width of x8, so this field is set to the PCI-SIG
defined value for x8, which is 001000 b, or 8h.
0001b
Maximum Link Speed (MLS): Intel® 6700PXH 64-bit PCI Hub supports a
PCI Express* link speed of 2.5 Gbps only, so this field is set to the PCI-SIG
defined value for 2.5 Gbps, which is 0001b, or 1h.
148
Intel® 6700PXH 64-bit PCI Hub Datasheet
INTEL [ INTEL ]
