HBM Verification: Why Controllers That Pass Tests Still Fail in Silicon

Why HBM Controllers Pass Verification — Yet Fail in Silicon

HBM controllers often pass every verification test — protocol, timing, and corner cases — yet still fail in real silicon.

This isn’t a tooling failure.
It’s a verification mindset gap.

Passing Tests Isn’t the Same as Surviving Reality

Most HBM verification focuses on functional correctness:

• Legal command sequences
• Timing compliance
• Clean state-machine behavior But silicon failures don’t come from illegal behavior. They come from legal behaviors colliding under system stress.

What Simulations Commonly Miss

In real systems, HBM operates under constant pressure:

• Refresh overlapping with heavy traffic
• Bank conflicts across multiple requesters
• Backpressure from interconnects
• Long-running contention and arbitration stress Each condition is legal on its own — together, they create deadlocks, starvation, or bandwidth collapse that simulations rarely expose.

The Real Verification Question

The real question isn’t:

“Does this controller pass tests?”

It’s:

“Can it make forward progress forever under stress?”

Verification must shift from correctness-only to resilience-focused testing.

Read the Full Analysis

This post summarizes why the problem exists.
The full article dives deeper into real silicon behavior and verification blind spots:

👉 Full article on WIOWIZ
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