PCI-to-PCI Bridge Registers (D30:F0)
11.1.13 MEMBASE_LIMIT—Memory Base and Limit Register
(PCI-PCI—D30:F0)
Offset Address: 20h–23h
Default Value: 00000000h
Attribute:
Size:
R/W
32 bits
This register defines the base and limit, aligned to a 1-MB boundary, of the non-
prefetchable memory area of the bridge. Accesses that are within the ranges specified
in this register will be sent to PCI if CMD.MSE is set. Accesses from PCI that are outside
the ranges specified will be accepted by the bridge if CMD.BME is set.
Bit
Description
Memory Limit (ML) — R/W. These bits are compared with bits 31:20 of the incoming
31:20 address to determine the upper 1-MB aligned value (exclusive) of the range. The
incoming address must be less than this value.
19:16 Reserved
Memory Base (MB) — R/W. These bits are compared with bits 31:20 of the incoming
15:4
3:0
address to determine the lower 1-MB aligned value (inclusive) of the range. The
incoming address must be greater than or equal to this value.
Reserved
11.1.14 PREF_MEM_BASE_LIMIT—Prefetchable Memory Base
and Limit Register (PCI-PCI—D30:F0)
Offset Address: 24h–27h
Default Value: 00010001h
Attribute:
Size:
R/W, RO
32-bit
Defines the base and limit, aligned to a 1-MB boundary, of the prefetchable memory
area of the bridge. Accesses that are within the ranges specified in this register will be
sent to PCI if CMD.MSE is set. Accesses from PCI that are outside the ranges specified
will be accepted by the bridge if CMD.BME is set.
Bit
Description
Prefetchable Memory Limit (PML) — R/W. These bits are compared with bits 31:20
31:20 of the incoming address to determine the upper 1-MB aligned value (exclusive) of the
range. The incoming address must be less than this value.
19:16 64-bit Indicator (I64L) — RO. Indicates support for 64-bit addressing.
Prefetchable Memory Base (PMB) — R/W. These bits are compared with bits 31:20
of the incoming address to determine the lower 1-MB aligned value (inclusive) of the
range. The incoming address must be greater than or equal to this value.
15:4
3:0
64-bit Indicator (I64B) — RO. Indicates support for 64-bit addressing.
Datasheet
363
INTEL [ INTEL ]
