Intel Xeon Wolfdale E3210 P4X-UPE3210-316-6M1333 Data Sheet
Product codes
P4X-UPE3210-316-6M1333
Datasheet
231
Host-Secondary PCI Express* Bridge Registers (D6:F0) (Intel
®
3210 MCH only)
8.24
BCTRL1—Bridge Control
B/D/F/Type:
0/6/0/PCI
Address Offset: 3E–3Fh
Default Value:
0000h
Access:
RO, RW
Size:
16 bits
This register provides extensions to the PCICMD1 register that are specific to PCI-PCI
bridges. The BCTRL provides additional control for the secondary interface as well as
some bits that affect the overall behavior of the "virtual" Host-PCI Express bridge
embedded within MCH.
Bit
Access
Default
Value
Description
15:12
RO
0h
Reserved
11
RO
0b
Discard Timer SERR# Enable (DTSERRE): Not Applicable or Implemented.
Hardwired to 0.
Hardwired to 0.
10
RO
0b
Discard Timer Status (DTSTS): Not Applicable or Implemented. Hardwired to
0.
0.
9
RO
0b
Secondary Discard Timer (SDT): Not Applicable or Implemented. Hardwired
to 0.
to 0.
8
RO
0b
Primary Discard Timer (PDT): Not Applicable or Implemented. Hardwired to
0.
0.
7
RO
0b
Fast Back-to-Back Enable (FB2BEN): Not Applicable or Implemented.
Hardwired to 0.
Hardwired to 0.
6
RW
0b
Secondary Bus Reset (SRESET): Setting this bit triggers a hot reset on the
corresponding PCI Express Port. This will force the LTSSM to transition to the Hot
Reset state (via Recovery) from L0, L0s, or L1 states.
corresponding PCI Express Port. This will force the LTSSM to transition to the Hot
Reset state (via Recovery) from L0, L0s, or L1 states.
5
RO
0b
Master Abort Mode (MAMODE): Does not apply to PCI Express. Hardwired to
0.
0.
4
RW
0b
VGA 16-bit Decode (VGA16D): Enables the PCI-to-PCI bridge to provide 16-
bit decoding of VGA I/O address precluding the decoding of alias addresses
every 1 KB. This bit only has meaning if bit 3 (VGA Enable) of this register is also
set to 1, enabling VGA I/O decoding and forwarding by the bridge.
0 = Execute 10-bit address decodes on VGA I/O accesses.
1 = Execute 16-bit address decodes on VGA I/O accesses.
bit decoding of VGA I/O address precluding the decoding of alias addresses
every 1 KB. This bit only has meaning if bit 3 (VGA Enable) of this register is also
set to 1, enabling VGA I/O decoding and forwarding by the bridge.
0 = Execute 10-bit address decodes on VGA I/O accesses.
1 = Execute 16-bit address decodes on VGA I/O accesses.
3
RW
0b
VGA Enable (VGAEN): Controls the routing of processor initiated transactions
targeting VGA compatible I/O and memory address ranges. See the VGAEN/
MDAP table in device 0, offset 97h[0].
targeting VGA compatible I/O and memory address ranges. See the VGAEN/
MDAP table in device 0, offset 97h[0].
2
RW
0b
ISA Enable (ISAEN): Needed to exclude legacy resource decode to route ISA
resources to legacy decode path. Modifies the response by the MCH to an I/O
access issued by the processor that target ISA I/O addresses. This applies only
to I/O addresses that are enabled by the IOBASE and IOLIMIT registers.
0 = All addresses defined by the IOBASE and IOLIMIT for processor I/O
resources to legacy decode path. Modifies the response by the MCH to an I/O
access issued by the processor that target ISA I/O addresses. This applies only
to I/O addresses that are enabled by the IOBASE and IOLIMIT registers.
0 = All addresses defined by the IOBASE and IOLIMIT for processor I/O
transactions will be mapped to PCI Express.
1 = MCH will not forward to PCI Express any I/O transactions addressing the last
768 bytes in each 1 KB block even if the addresses are within the range
defined by the IOBASE and IOLIMIT registers.
defined by the IOBASE and IOLIMIT registers.