MBIST & LBIST

Section goal

Memory and logic BIST architecture, repair flows, and BIST signoff criteria.

How to study this section

1. Start with the topic hub for architecture and ownership context.

2. Use mechanism and reports pages to map assumptions to metrics.

3. Use debug and worked examples for real closure patterns.

4. Finish with checklist and silicon impact before release decisions.

Topics

1. mbist-integration/ - MBIST Integration

2. memory-repair-flow/ - Memory Repair Flow

3. lbist-overview/ - LBIST Overview

4. bist-signoff/ - BIST Signoff

Related topics

• DFT course hub

DFT deep dive

BIST value is realized only when insertion, diagnosis, and repair are tied to production flow.

Concept diagram

BIST FLOW

insert MBIST/LBIST -> execute -> collect signatures -> diagnose/repair -> signoff

Metric graph

REPAIR EFFECT

yield
  ^
  |      o pre-repair
  |             o post-repair
  +---------------------> lot

Reports and artifacts

• MBIST insertion coverage

• repair signature report

• LBIST resistant fault list

• BIST release checklist

Mini case study

Fuse programming mismatch blocked repair activation; corrected bring-up script recovered expected yield uplift.

Debug branches

• Validate BIST reachability

• Correlate fail maps to repair signatures

• Audit in-field boot test budget

Senior review question

Ask: what evidence proves this DFT decision is safe for production?