Renesas 89HPES24T3G2ZBAL, User Manual

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IDT Configuration Registers
PES24T3G2 User Manual 8 - 59 February 22, 2012
Notes
10:9 DDDNC RW 0x0
Sticky
Disable Downstream Device Number Checking. According to
Section 7.3.1. Device Number in PCIe base 2.0, configuration
requests specifying target device 0 in a bus number associated
with a downstream link are delivered to the device attached to the
link; configuration requests specifying all other device numbers
(1-31) must be terminated by the switch downstream port with an
unsupported request.
This field controls the extent to which device numbers are
checked by downstream ports.
This field is present for backwards compatibility with earlier IDT
switches that implement a proprietary version of ARI forwarding.
This field has no functional effect on the operation of a port when
the ARI Forwarding Enable (ARIFEN) bit is set in the port’s PCI
Express Device Control 2 (PCIEDCTL2) register.
0x0 -
(all) Inhibit the transmission of all TLPs that are routed by
ID, specify a bus number associated with a downstream
port link, and specify a device number other than zero.
0x1 - (cfg) Inhibit the transmission of configuration request
TLPs that are routed by ID, specify a bus number associ-
ated with a downstream port link, and specify a device
number other than zero. Non-configuration request TLPs
are delivered to the device attached to a link associated
with a downstream switch port regardless of the speci-
fied device number.
0x2 - (none) All TLPs are delivered to the device attached to a
link associated with a downstream switch port regardless
of the specified device number.
0x3 - reserved
11 EUIDC RW 0x0
Sticky
Enable Upstream Port ID Checking. Normally TLPs with a non-
zero device number that target the bus number corresponding to
the upstream link and are received on a downstream port are for-
warded upstream and are emitted on the upstream link.
When this bit is set, these request TLPs are treated as unsup-
ported requests (UR) and completion TLPs are silently discarded.
This field should be documented
13:12 Reserved RO 0x0 Reserved field.
14 CTDIS RW 0x0
Sticky
Disable Cut-Through Routing. When this bit is set, cut through
routing of TLPs is disabled between all ports (i.e., they are routed
in a stored and forwarded manner). When this bit is cleared,
TLPs are routed in a cut-through manner when possible.
15 LOCK-
IGNORE
RW 0x0
Sticky
Ignore Locked Transactions When this bit is set, all bus locking
side-effects associated with locked transactions (e.g., MRdLk)
are ignored and the TLPs are treated by the PES24T3G2 as nor-
mal TLPs (e.g., are routed normally through the switch).
18:16 Reserved RO 0x0 Reserved field.
19 BDISCARD RW 0x0
Sticky
Discard Vendor Defined Broadcast Messages. When this bit is
set, vendor defined Type 1 broadcast messages received on the
upstream port are silently discarded and not forwarded down-
stream.
Silently discarding a TLP means that flow control credits are
returned, TLP contents are discarded, and no error bits are set.
Bit
Field
Field
Name
Type
Default
Value
Description