IDT PCI Express 89HPES32NT24xG2, User Manual, Page: 118 / 744

IDT Switch Partition and Port Configuration
PES32NT24xG2 User Manual 5 - 18 January 30, 2013
Notes
INTx Interrupt Signaling
Removing an upstream port from a partition has no effect on the partition since the interrupt state is
associated with the root located above the upstream port that is being removed. An INTx state change
signaled by a downstream switch port in the source partition has no effect on the upstream port as the latter
is no longer associated with the partition.
Removing a downstream switch port from a partition has the affect of removing all INTx virtual wire
assertions associated with the port (i.e., INTA, INTB, INTC and INTD from the port are negated).
Mode Change Effect on Destination Partition
A port operating mode change that results in a port being added to a partition has the following effect on
that partition (i.e., the destination partition). Some of the behaviors described below rely on the state of the
port. The state of the port and its corresponding configuration registers are determined by the OMA field as
described in
section No Action Mode Change Behavior on page 5-21.
Partition Hot Reset
See section Partition Hot Reset on page 3-12 for an overview of partition hot reset. The addition of an
upstream port that is initiating a hot reset (i.e., as the result of reception of TS1 ordered sets with the hot
reset bit set or DL_Down) has the effect of initiating a partition hot reset to the destination partition as
described in section Partition Hot Reset on page 3-12.
– An upstream port whose link transitioned to the Detect state (i.e., DL_Down) as a result of the
operating mode change may trigger a hot reset in the destination partition as described in section
Partition Hot Reset on page 3-12.
The addition of a downstream switch port to a destination partition that has a partition hot reset in prog-
ress does not have an effect on the ongoing hot reset in the destination partition (i.e., the hot reset opera-
tion continues normally on the other ports in the partition). The added downstream switch port participates
in the ongoing hot reset after the addition of the port has completed.
Partition Upstream Secondary Bus Reset
See section Partition Upstream Secondary Bus Reset on page 3-13 for an overview of partition
upstream secondary bus reset. The addition of an upstream switch port whose SRESET bit in the BCTL
register of the port’s PCI-to-PCI bridge function is set, has the effect of initiating a partition upstream
secondary bus reset. The addition of a downstream switch port to a destination partition that has an
upstream secondary bus reset in progress does not have an effect on the ongoing hot reset in the destina-
tion partition (i.e., the hot reset operation continues normally on the other ports in the partition). The added
downstream switch port participates in the ongoing hot reset after the addition of the port has completed.
Partition Downstream Secondary Bus Reset
See section Partition Downstream Secondary Bus Reset on page 3-14 for an overview of partition
downstream secondary bus reset. The addition of a downstream switch port whose SRESET bit in the
BCTL register is set has no effect on the destination partition since other ports in the partition are unaffected
by this type of reset (i.e., the hot reset is propagated to the endpoint located below the port that is being
removed).
Routing
Adding a port to a partition results in the routing specified by the configuration registers associated with
that port being enabled in the destination partition. For example, adding a downstream switch port to a
partition causes all other ports in the partition to validate routes to the moved downstream switch port. Also,
adding an upstream port to a partition causes all downstream switch ports in the partition to validate routes
to the function(s) in the moved upstream port.
Finally, adding an upstream port that contains an NT function to a partition causes all other NT functions
to validate routes to the affected partition.