2. RapidIO Ports > Reset Control Symbol Processing
CPS-1848 User Manual
41
June 2, 2014
Formal Status
This document is confidential and is subject to an NDA.
Integrated Device Technology
5. The next transmitted and received ackID values are reset to 0. The next packet to be transmitted by the port will have ackID
0. The expected ackID of the next packet is 0.
6. Detectable errors on control symbols or packets received by the port in the cycle in which the reset event occurs are ignored.
7. Packets stored in the port’s input buffer are discarded.
8. Packets stored in the crosspoint buffers that feed the port’s final buffer of the port are discarded while the port is held in reset.
9. Packets stored in the port’s final buffer are discarded.
10.The
Port {0..17} Error and Status CSR
— PORT_UNINIT is set to 1
— PORT_OK is set to 0
— INPUT_ERR_STOP is set to 0
— INPUT_ERR is set to 0
— INPUT_RETRY_STOP is set to 0
— OUTPUT_ERR_STOP is set to 0
— OUTPUT_ERR is set to 0
— OUTPUT_RETRY_STOP is set to 0
— OUTPUT_RETRIED is set to 0
— OUTPUT_RETRY is set to 0
— PORT_ERR is set to 0 (Revision C)
11. The link begins to retrain, starting from the SILENT state.
If many congested ports were sending packets to the reset port, some packets may exist in the final
buffer after the reset. It is also possible for maintenance responses to be sent after the reset because
maintenance requests with a hop count of 0 are processed outside of the receiving port.
The following is applicable to Revision A/B.
PORT_ERR is not cleared by a per-port reset. If PORT_ERR is set then the port will drop all packets
routed to the Final Buffer, including maintenance packet responses.
To recover, the port must send a Link-Request/Input Status control symbol and receive a response.
This will clear the PORT_ERR and packet drop condition. The CPS-1848 will send a
Link-Request/Input Status control symbol when either of the following occurs:
• A Packet Not Accepted control symbol is received
• 0b100 is written to the
Port {0..17} Link Maintenance Request CSR
For more information on clearing PORT_ERR, see
Routing table programming is retained after a per-port reset.
All registers other than the registers referenced above retain the values they had before the per-port
reset request was received.
Writing to the
Port {0..17} Link Maintenance Request CSR
for the correct port requires knowledge of the
port number on the link partner. If it is possible to be connected to one of many ports, it is necessary to
write to the
Port {0..17} Link Maintenance Request CSR
for each port.