IDT PCI Express 89HPES32NT24xG2, User Manual, Page: 273 / 744

IDT Non-Transparent Switch Operation
PES32NT24xG2 User Manual 14 - 25 January 30, 2013
Notes
Figure 14.12 Example of ACS Peer-to-Peer Request Re-direct Applied by the NT Function
When multiple ACS checks are enabled, they are prioritized as described in Chapter 10, Tables 10.4
and 10.5. Refer to the PCI Express Base Specification for further information on ACS.
Error Detection and Handling by the NT Function
This section describes error conditions associated with non-transparent switch operation. This includes
physical, data-link, and transaction layer errors detected by the switch ports, as well as application layer
errors associated with the non-transparent-bridge (NTB) functionality.
– Internal switch errors (i.e., parity errors, switch time-out, and internal memory errors) are associ-
ated with the switch core and not with a specific port function. These errors are not described here.
Refer to section Internal Errors on page 4-16 for a detailed description of these errors.
The errors described here apply to ports that operate in a mode that includes the NT function (e.g., NT
endpoint mode, upstream switch port with NT endpoint mode, etc.) This section focuses specifically on
errors related to the NT function
1
. Errors that affect all functions of the port (i.e., non function-specific errors)
are noted where appropriate.
Error detection and handling in the PES32NT24xG2 follows the requirements in the PCI Express Base
Specification.
The error checking and handling described here is performed by each PES32NT24xG2 NT function. In
cases where the error condition propagates among multiple NT functions (e.g., a poisoned TLP received by
an NT function, passed across the NT interconnect, and emitted by the NT function in another partition),
each NT function performs error checking and handling independently. Refer to section NTB Inter-Partition
Error Propagation on page 14-31 for further details and examples on this.
The errors described below are associated with specific actions to log and report the error. The terms
‘uncorrectable error processing’ and ‘correctable error processing’ refer to the processing described in
Section 6.2.5 of PCI Express Base Specification.
Errors which are not function-specific are logged in the corresponding status and logging registers of all
functions in the port. Errors that are function-specific are logged in the status and logging register of the
affected function only. Signaling of non function-specific errors follows the rules in Section 6.2.4 of PCI
Express Base Specification.
1.
Errors associated with the PCI-to-PCI bridge function (i.e., transparent operation errors) are described in
Chapter 10. Errors associated with the DMA function are described in Chapter 15.
Partition 1 – Virtual PCI Bus
P2P
Bridge
Upstream
Port
P2P
Bridge
P2P
Bridge
Upstream
Port
Partition 2 – Virtual PCI Bus
P2P
Bridge
P2P
Bridge
P2P
Bridge
NT
Endpoint
NT
Endpoint
Downstream Ports
Non Transparent
Interconnect
Intended TLP Route
ACS Re-directed Route
ACS Peer-to-
Peer Request
Redirect