Datasheet

System Address Map
Intel
®
Xeon
®
Processor C5500/C3500 Series
Datasheet, Volume 1 February 2010
334 Order Number: 323103-001
Table 105, “Subtractive Decoding of Outbound I/O Requests from Intel® QPI” details
IIO behavior when no target has been positively decoded for an incoming I/O
transaction from Intel
®
QPI.
Table 104. Decoding of Outbound Configuration Requests from Intel
®
QPI and Decoding
of Outbound Peer-to-Peer Completions from Intel
®
QPI
Address
Range
Conditions
IIO Behavior
Bus 0
Bus 0 and legacy IIO and device number
matches one of internal device numbers
Forward to that internal device.
Bus 0 and legacy IIO and device number does
NOT match one of IIO’s internal device numbers
If remote peer-to-peer configuration
transaction, master abort, else forward to
the downstream subtractive decode port
i.e. the legacy DMI port
If the transaction is a configuration
request, the request is forwarded as a Type
0
1
configuration transaction to the
subtractive decode port
Bus 0 and NOT legacy IIO Master Abort
Bus 1-255
Bus 1-255 and it matches the IOHBUSNO and
device number matches one of the IIO’s internal
device numbers
If remote peer-to-peer configuration
transaction, master abort, else forward to
that internal device.
Bus 1-255 and it matches the IOHBUSNO and
device number does NOT match any of the IIO’s
internal device numbers
Master Abort
Bus 1-255 and it does not match the IOHBUSNO
but positively decodes to one of the downstream
PCIe ports
Forward to that port.
Configuration requests are forwarded as a
Type 0
2
(if bus number matches secondary
bus number of port) or a Type 1.
Bus 1-255 and it does not match the IOHBUSNO
and does not positively decode to one of the
downstream PCIe ports and DMI is the
subtractive decode port
Forward to DMI
3
.
Forward configuration request as Type 0/1,
depending on secondary bus number
register of the port.
Bus 1-255 and it does not match the IOHBUSNO
and does not positively decode to one of the
downstream PCIe ports and DMI is not the
subtractive decode port
Master Abort
1. When forwarding to DMI, Type 0 transaction with any device number is required to be forwarded by the IIO
(unlike the standard PCI Express root ports)
2. If a downstream port is a standard PCI Express root port, then PCI Express spec requires that all non-zero-
device numbered Type0 transactions are master aborted by the root port. If the downstream port is non-
legacy DMI, then Type 0 transaction with any device number is allowed/forwarded.
3. When forwarding to DMI, Type 0 transaction with any device number is required to be forwarded by the IIO
(unlike the standard PCI Express root ports)
Table 105. Subtractive Decoding of Outbound I/O Requests from Intel
®
QPI
Address
Range
Conditions
1
IIO Behavior
Any I/O
address not
positively
decoded
No valid target decoded and one of the downstream
ports is the subtractive decode port
Forward to downstream subtractive
decode port
No valid target decoded and none of the downstream
ports is the subtractive decode port
Master Abort
1. See description before this table for clarification of what is actually described in the table.
Table 104, “Decoding of Outbound Configuration Requests from Intel® QPI and
Decoding of Outbound Peer-to-Peer Completions from Intel® QPI” details IIO behavior
for configuration requests from Intel
®
QPI and peer-to-peer completions from Intel
®
QPI.