Altera Arria V Hard IP for PCI Express - Manual (Page 205)

Chapter 12: Optional Features 12–3
ECRC
December 2013 Altera Corporation Arria V Hard IP for PCI Express
User Guide
Table 12–1 summarizes the RX ECRC functionality for all possible conditions.
ECRC on the TX Path
When the ECRC generation option is on, the TX path generates ECRC. If you turn on
ECRC forwarding
, the ECRC value is forwarded with the TLP. Table 12–2
summarizes the TX ECRC generation and forwarding. In this table, if TD is 1, the TLP
includes an ECRC. TD is the TL digest bit of the TL packet described in Appendix A,
Transaction Layer Packet (TLP) Header Formats .
Table 12–1. ECRC Operation on RX Path
ECRC
Forwarding
ECRC
Check
Enable (1)
ECRC
Status
Error TLP Forward to Application Layer
No
No
none No Forwarded
good No Forwarded without its ECRC
bad No Forwarded without its ECRC
Yes
none No Forwarded
good No Forwarded without its ECRC
bad Yes Not forwarded
Yes
No
none No Forwarded
good No Forwarded with its ECRC
bad No Forwarded with its ECRC
Yes
none No Forwarded
good No Forwarded with its ECRC
bad Yes Not forwarded
Note to Table 12–1 :
(1) The ECRC Check Enable is in the Configuration Space Advanced Error Capabilities and Control
Register.
Table 12–2. ECRC Generation and Forwarding on TX Path (1)
ECRC
Forwarding
ECRC
Generation
Enable (2)
TLP on Application
Layer
TLP on Link Comments
No
No
TD =0, without ECRC TD =0, without ECRC
TD =1, without ECRC TD =0, without ECRC
Yes
TD =0, without ECRC TD =1, with ECRC
ECRC is generated TD =1, without ECRC TD =1, with ECRC
Yes
No
TD =0, without ECRC TD =0, without ECRC
Core forwards the
ECRC
TD =1, with ECRC TD =1, with ECRC
Yes
TD =0, without ECRC TD =0, without ECRC
TD =1, with ECRC TD =1, with ECRC
Notes to Table 12–2 :
(1) All unspecified cases are unsupported and the behavior of the Hard IP is unknown.
(2) The ECRC Generation Enable is in the Configuration Space Advanced Error Capabilities and
Control Register.