SoC Integration · All levels

AXI/ACE Contracts: Comparison Matrix

Comparison Matrix for AXI/ACE Contracts.

Comparison matrix

NoC/AXI policy choices trade fairness, throughput, and determinism.

diagram

+------------------+----------------+----------------+----------------+
| Approach         | Strength       | Weakness       | Best when      |
+------------------+----------------+----------------+----------------+
| Strict           | predictable    | slower early   | new program    |
| Balanced         | practical      | needs rigor    | stable teams   |
| Aggressive       | fast           | escape risk    | late schedule  |
| Re-architect     | durable        | expensive      | recurring failures |
+------------------+----------------+----------------+----------------+

When to choose each approach

Pick the approach based on residual silicon risk, not only schedule pressure.

Review traps

Policy-only arguments without artifact evidence
Unbounded waivers

Evidence comparison

diagram

INTEGRATION EVIDENCE MATRIX — AXI/ACE Contracts

+-------------------+------------------------+--------------------------+-------------------------+
| Evidence           | Tells you              | Does not prove           | Next action             |
+-------------------+------------------------+--------------------------+-------------------------+
| Manifest diff      | baseline changed       | root cause itself        | isolate first delta     |
| Domain trace       | where behavior diverged| ownership accountability | map to contract owner   |
| Signoff dashboard  | closure posture        | reproducibility quality  | verify source artifacts |
| Bring-up logs       | software-visible symptom| physical/timing cause   | correlate with HW trace |
| Waiver register    | accepted residual risk | technical closure        | review expiry criteria  |
+-------------------+------------------------+--------------------------+-------------------------+

SoC deep dive

Fabric correctness and contention behavior must be proven together.

Concept diagram

diagram

FABRIC FLOW
masters -> routers/VCs -> slaves + memory

Metric graph

diagram

LATENCY TAIL
p50 ███
p95 ██████
p99 ██████████

Reports and artifacts

NoC contention heatmap
ordering violation report
QoS fairness summary
protocol trace

Mini case study

Bandwidth looked fine at average load, but p99 tail violated SLA due to arbitration starvation.

Debug branches

Isolate traffic class
Check ordering assumptions
Audit arbitration policy

Senior review question

Ask: what baseline, owner, and artifact prove this topic is truly closed?

Key takeaways

State baseline manifest and owner with every closure metric.
Run cross-domain regression after every top-level fix.

Common pitfalls

Comparing results across different manifests.
Unowned issues slipping through review cycles.
Waiving risks without expiry and validation plan.

Principal SoC review addendum

AXI/ACE integration depends on preserving ID, ordering, coherency attributes, and sideband semantics through bridges and fabric adapters.

Metric: ordering violations, protocol error rate, outstanding depth stability

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