RISC-V Design ยท All levels
Forwarding Network and Stall Control for Data Hazards: Worked Example
Worked Example for Forwarding Network and Stall Control for Data Hazards.
Worked example
Worked Example for Forwarding Network and Stall Control for Data Hazards is anchored on RAW hazard coverage percentage with zero incorrect-commit events and minimum load-use stall cycles per kilo-instruction.. Convert observations into mechanism-backed decisions with explicit ownership.
A regression flags RAW hazard coverage percentage with zero incorrect-commit events and minimum load-use stall cycles per kilo-instruction.. Strong closure isolates first failing mechanism, proves causality, applies one bounded change, and validates blast radius.
System view
RISC-V PIPELINE DIAGRAM - Forwarding Network and Stall Control for Data Hazards
PC -> IF -> ID -> EX -> MEM -> WB
| | | | |
i-cache decode ALU/BR LSU regfile write
\ |
+-> branch resolve + redirect
Hot paths:
- branch + load-use dependencies in ID/EX
- memory latency stretching MEM stage
- writeback arbitration for integer/vector units
Focus: keep control hazards predictableEvidence matrix
RISC-V EVIDENCE MATRIX - Forwarding Network and Stall Control for Data Hazards
+--------------------------+--------------------------------+--------------------------------+---------------------------+
| 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 |
+--------------------------+--------------------------------+--------------------------------+---------------------------+Capture baseline and failing traces under fixed metadata tags.
Classify stage loss and dominant mechanism.
Collect Forwarding select truth table, hazard detector pseudocode, and stall/bubble state machine timing diagram..
Apply one bounded fix with owner signoff.
Run validation matrix and decide ship/rollback.