IDT PCI Express 89HPES32NT24xG2, User Manual, Page: 317 / 744

IDT DMA Controller
PES32NT24xG2 User Manual 15 - 29 January 30, 2013
Notes
In addition, some of the errors described below are marked as function-specific when the “function
claims the TLP”. Some of the errors described below are marked as function-specific when the “function
claims the TLP”. A function claims a TLP in the following cases:
– DMA function:
• Address Routed TLPs: The TLP address falls within the address space range(s) programmed
in the DMA’s base address registers (BARs).
• ID Routed TLPs: The TLP destination ID matches the DMA’s bus/device/function assignment
within the PCI Express hierarchy.
• Implicit Route TLPs: Always.
– PCI-to-PCI Bridge function
• Refer to section Error Detection and Handling by the PCI-to-PCI Bridge Function on page 10-11.
– NT Endpoint function:
• Refer to section Error Detection and Handling by the NT Function on page 14-25.
PCI Express errors associated with the DMA function are categorized into physical, data-link, and trans-
action layer errors.
Physical Layer Errors
All physical layer errors are non-function specific. These errors are described in the error handling
section for the PCI-to-PCI bridge function. Refer to section Physical Layer Errors on page 10-11 .
Data Link Layer Errors
All data link layer errors are non-function specific. These errors are described in the error handling
section for the PCI-to-PCI bridge function. Refer to section Data Link Layer Errors on page 10-12.
Transaction Layer Errors
Table 15.12 lists all the PCI Express error checks performed by the DMA function’s transaction layer as
well as the action taken when an error is detected. Per PCI Express Base Specification 2.1, transaction
layer errors are ignored in cases where the error is associated with a received packet for which the physical
or data-link layers report an error. This prevents error pollution across the layers.
Within the transaction layer, there are error pollution rules that resolve the cases where two or more
errors are detected simultaneously. Refer to section Error Pollution on page 15-34 for details on transaction
layer error pollution in the DMA function.
Table 15.12 indicates if the detected errors are specific to a DMA channel (i.e., channel-specific errors).
Channel-specific errors only affect the DMA channel associated with the error. Non channel-specific errors
affect all or none of the DMA channels. The determination is done on an error by error basis as described in
the sections below.
For some errors, it is necessary to determine if the function that receives a TLP from the link is an “ulti-
mate receiver” or “intermediate receiver”. The DMA function is always considered an ultimate receiver when
the TLP is received directly from the link.