IDT Transparent Mode Operation
End-to-End CRC
PES12N3 User Manual
9 - 2
June 7, 2006
Notes
End-to-End CRC
PCIe® defines an optional end-to-end CRC associated with TLPs.
The PES12N3 fully supports ECRC for all TLPs that pass through the switch except for transactions
utilizing gathered and routed to root complex implicit routing. For transactions received with this routing
type, the ECRC is discarded and not checked and the resulting gathered message is generated without an
ECRC. The only standard defined message that utilizes this method of routing is the PME_TO_Ack
message.
The PES12N3 does not support ECRC for TLPs that it generates (e.g., configuration responses, INTx
messages, etc.). Also, it does not support ECRC for TLPs it consumes (e.g., configuration requests).
However; if a TLP is received with an ECRC, the CRC is discarded and not checked and the transaction is
performed.
Interrupts
The upstream port, port A, does not support generation of legacy interrupts or MSIs. The downstream
ports, ports B and C, do support generation of legacy interrupts and MSIs by their corresponding hot-plug
controllers. When configured to generate INTx messages, only INTA is used.
When an unmasked hot-plug interrupt condition occurs (see section Hot-Plug Interrupts and Wake-up
on page 6-6), then an MSI or interrupt message is generated by the corresponding port as described in
Table 9.1. The removal of the interrupt condition occurs when unmasked hot-plug status bits are masked or
cleared.
Error Detection and Handling
This section describes error detection performed by an ingress or egress stack when the switch is
configured to operate in transparent mode. Table 9.2 lists error checks performed by the physical layer and
action taken when an error is detected.
Unmasked
Hot-Plug
Interrupt
EN bit in
MSICAP
Register
INTXD bit
in PCICMD
Register
Action
Asserted
1
X
MSI message generated
0
0
Assert_INTA message request generated to switch
core
0
1
None
Negated
1
X
None
0
0
Deassert_INTA message request generated to
switch core
0
1
None
Table 9.1 Transparent Mode Port B and C Interrupts
Summary of Contents for 89HPES12N3
Page 10: ...IDT Table of Contents PES12N3 User Manual iv June 7 2006 Notes...
Page 14: ...IDT List of Figures PES12N3 User Manual viii June 7 2006 Notes...
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Page 54: ...IDT Power Management Active State Power Management PES12N3 User Manual 5 4 June 7 2006 Notes...
Page 62: ...IDT Hot Plug and Hot Swap Hot Swap PES12N3 User Manual 6 8 June 7 2006 Notes...
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