AIE_CASCADE_STALLS - 2022.2 English

Vitis Guidance Messaging (UG1315)

Document ID
UG1315
Release Date
2022-10-19
Version
2022.2 English

Description

This rule checks the amount of cascade stalls for AI Engine tiles.

Default Threshold

20.0

Explanation

Reducing cascade stalls can improve AI Engine performance. Time AI Engine was in a cascade stall. This could be due to multiple reasons such as cascade streams being read faster than they are written to streams from the PL being clocked at a slower frequency, etc.

Recommendation

See this link in AI Engine Tools and Flows User Guide (UG1076) for AIE_CASCADE_STALLS.

You can resolve the stall by examining stream access patterns using trace results and adjusting the instructions in the loop to match between the input/output streams or maximizing the PL bandwidth to the AI Engine.

  • Adjust instructions in the loop.