Host Bridge/DRAM Controller Registers (D0:F0)
R
54 Intel
®
82925X/82925XE MCH Datasheet
4.1.12 EPBAR—Egress Port Base Address (D0:F0)
PCI Device: 0
Address Offset: 40h
Default Value: 00000000h
Access: RO
Size: 32 bits
This is the base address for the Egress Port MMIO configuration space. There is no physical
memory within this 4-KB window that can be addressed. The 4 KB reserved by this register does
not alias to any PCI 2.3 compliant memory mapped space.
On reset, this register is disabled and must be enabled by writing a 1 to EPBAREN[Dev 0, offset
54h, bit 27]
Bit Access &
Default
Description
31:12 R/W
00000h
Egress Port MMIO Base Address: This field corresponds to bits 31 to 12 of the
base address Egress Port MMIO configuration space.
BIOS will program this register resulting in a base address for a 4-KB block of
contiguous memory address space. This register ensures that a naturally aligned
4-KB space is allocated within total addressable memory space of 4 GB.
System software uses this base address to program the MCH MMIO register set.
11:0 Reserved