MACsec Intel® FPGA IP User Guide

ID 736108
Date 10/21/2022
Public

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6.1.9. Controlled/Uncontrolled Port Muxing

The diagram below shows the arbitration mux between the Controlled and Uncontrolled ports on the Tx encryption lane. The Uncontrolled port traffic is directly taken from the user while the Controlled port traffic is output from the Encryption Deframer block.
Figure 28. Controlled/Uncontrolled Port Muxing


The Encryption Deframer output can interleave 64-byte words from different streams. The Uncontrolled port traffic requirements are specified below.

Table 41.  Uncontrolled Port Traffic Requirement
Cycle 0 1 2 3 4 5 6
Stream 0 0 3 3 4 7 7
Data[127:0] SOP EOP SOP Data SOP SOP Data
Data[255:128] Data IDLE Data Data Data Data EOP
Data[383:256] Data IDLE Data Data Data Data IDLE
Data[511:384] Data IDLE Data EOP EOP Data IDLE
  • Packet based per stream
  • Single Packet Mode only
  • No interleaving of packets with different stream packest
  • The arbitration between the Uncontrolled and Controlled ports follows the following criteria.
  • Priority of the port grant is based on the CSR setting (MACsec Control CSR bit 0)
  • When priority is configured to the Controlled port:
    • Traffic from the Uncontrolled port is not granted when the Controlled port has incoming traffic.
    • Traffic from the Uncontrolled port is not granted when the Controlled port traffic targeting the same stream as the Uncontrolled Port is not reaching EOP.
    • Traffic from the Uncontrolled port is not granted when the Controlled port traffic targeting the same stream as the Uncontrolled port is reaching EOP but there is another SOP within the same cycle.
    • Traffic from the Uncontrolled port is granted when the Controlled port traffic reaches EOP and none of the above is met.
  • When priority is configured to the Uncontrolled port (currently not supported, future enhancement):
    • Traffic from the Controlled port is granted when the Uncontrolled port traffic reaches EOP.
    • Traffic from the Controlled port is continuously granted until the Controlled port traffic targeting the same stream as the Uncontrolled port reaches EOP.