Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

13.4.4.3. Passing QOS across NoCs

As transactions cross multiple NoCs (for example, PSS NoC to CCU to MPFE NoC), QoS values must be propagated along with the transaction for it to be used at every stage of arbitration.

Both the PSS NoC and the MPFE NoC use urgency internally. It must be converted/remapped to AxQOS at external interfaces.

  • PSS NoC initiators generate urgency using internal QoS generators, converting it to AxQOS at the CCU_IOM target.
  • PSS NoC also receives AxQOS on CCU_IOM initiator, converting it to urgency to be used internally.
  • The MPFE NoC receives AxQOS as inputs on its initiators and convert it to urgency for arbitration by the DDR scheduler.