RISC-V Design · All levels

Privilege Levels, Execution Modes, and Delegation Boundaries: Design Space

Design Space for Privilege Levels, Execution Modes, and Delegation Boundaries.

Design space

Design Space for Privilege Levels, Execution Modes, and Delegation Boundaries is anchored on Privilege-transition latency and number of unauthorized accesses blocked by PMP/page-permission checks per billion instructions.. Convert observations into mechanism-backed decisions with explicit ownership.

  • Trade latency and throughput against power and area.

  • Prefer architecture options with clear software contract impact.

  • Quantify extension-profile cost before enabling by default.

  • Keep bring-up and validation ownership explicit.

Trend lens

diagram
BEFORE / AFTER TREND - Privilege Levels, Execution Modes, and Delegation Boundaries

Privilege-transition latency and number of unauthorized accesses blocked by PMP/page-permission checks per billion instructions.
  ^
  |                           o target band
  |                    o after fix + reruns
  |             o
  |      o baseline (failing)
  +--------------------------------------------------> iteration
       capture issue      isolate mechanism      close + monitor

Use this view to confirm the gain is causal and stable across seeds.