RISC-V Design · All levels
Forwarding Network and Stall Control for Data Hazards: Theory Deep Dive
Theory Deep Dive for Forwarding Network and Stall Control for Data Hazards.
Theory deep dive
Theory Deep Dive 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.
Theory matters when it predicts engineering outcomes. Tie abstract ISA and microarchitecture concepts to measurable behavior in trace and counter data.
Pipeline model
diagram
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 predictablePrivilege model
diagram
PRIVILEGE MODE STACK - Forwarding Network and Stall Control for Data Hazards
+------------------------------+
| Machine mode (M) |
| firmware, PMP, trap root |
+---------------+--------------+
|
delegated traps
v
+------------------------------+
| Supervisor mode (S) |
| kernel, page tables, drivers |
+---------------+--------------+
|
ecall / syscall
v
+------------------------------+
| User mode (U) |
| applications, libraries |
+------------------------------+
Key rule: each upward transition records cause + PC in trap CSRs.