Quality of Service
You can program the TCU with a priority level for each TBU. The priority level is applied to every translation from that TBU.
The TCU uses this priority level to:
- Arbitrate between translations that are waiting in the translation request buffer when translation manager slots become available.
- Arbitrate between translation manager slots when they access the caches and perform configuration table walks and translation table walks.
- Determine the AXI AxQOS value for translation table walks and configuration table walks that the TCU issues on the QTW/DVM interface.
The arbiters contain starvation avoidance mechanisms to prevent transactions from being stalled indefinitely.
The TBU does not implement any prioritization between transactions. Arm recommends that bus masters with different QoS requirements use separate TBUs for translation.