RISC-V Design · All levels

CSR Programming Model, Privilege Visibility, and Timer Facilities: Comparison Matrix

Comparison Matrix for CSR Programming Model, Privilege Visibility, and Timer Facilities.

Comparison matrix

Comparison Matrix for CSR Programming Model, Privilege Visibility, and Timer Facilities is anchored on CSR read/write hazard rate, timer interrupt accuracy (ns error), and software context-switch overhead attributable to CSR traffic.. Convert observations into mechanism-backed decisions with explicit ownership.

diagram
RISC-V EVIDENCE MATRIX - CSR Programming Model, Privilege Visibility, and Timer Facilities

+--------------------------+--------------------------------+--------------------------------+---------------------------+
| Evidence                 | Tells you                      | Does not prove                 | Next action               |
+--------------------------+--------------------------------+--------------------------------+---------------------------+
| perf counter timeline    | where regression appears       | exact mechanism causality      | correlate with trace      |
| decode/control dump      | control intent per instruction | pipeline side-effect ordering  | inspect retire semantics  |
| trap + CSR logs          | privilege/fault behavior       | performance bottleneck alone   | pair with CPI buckets     |
| MMU/TLB walk trace       | translation behavior           | full system QoS impact         | test mixed workloads      |
| post-fix trend graph     | movement after fix             | long-term stability            | run stress matrix         |
+--------------------------+--------------------------------+--------------------------------+---------------------------+