4. Addressing > Non-transparent Addressing
38
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
•
SecPFAddr = PriPFAddr - PriSecPFDiff, where
—
SecPFAddr
:
Defines the remapped address the PEB383 presents on PCI bus.
—
PriPFAddr
:
Defines the address presented to the PEB383 that falls within the registers
described in the previous paragraph.
—
PriSecPFDiff
: See previous bullet.
4.7.3
PCI to PCIe Address Remapping
Because the addresses of the downstream memory windows on the PCI bus have been shifted from
their locations on the PCIe link, the address range of cycles that a bridge will not claim on the PCI bus
must also be shifted. Therefore, memory cycles with addresses from SecNPBase (see
Non-prefetchable Address Remap Control Register”
and
“Secondary Bus Non-prefetchable Upper
) to SecNPLimit or from SecFPBase (see
Address Remap Control Register”
and
“Secondary Bus Prefetchable Upper Base Address Remap
) to SecFPLimit will not be claimed by the bridge on the PCI bus.
The Secondary Bus Non-prefetchable Limit is described in the following equation:
•
SecNPLimit = PriNPLimit - PriSecNPDiff, where
—
PriNPLimit
:
“PCI Memory Base and Limit Register”
Bus Non-prefetchable Upper Limit Remap Register”
.
—
PriSecNPDiff
: Defines the difference between the Primary Non-prefetchable Base and the
Secondary Non-prefetchable Base.
The Secondary Prefetchable Limit is described in the following equation:
•
SecPFLimit
=
PriPFLimit
-
PriSecPFDiff
, where
—
PriPFLimit
:
Defined by
“PCI PFM Base and Limit Register”
—
PriSecPFDiff
: Defines the difference between the Primary Prefetchable Base and the
Secondary Prefetchable Base.
Once the address is claimed as defined above, a memory cycle is forwarded from the PCI bus to the
PCIe link with its address modified according to the Non-transparent Address (NTMA) remapping
windows (see offsets 0x68 to 0x7C):
•
NTMA window remapping