pillar

DFT: What is March Algorithm? #Checkerboard

korean

DFT: What is March Algorithm? #Checkerboard

Logic 디자인 쪽만 하다가 DFT Lab에 처음 들어오면 제일 당황하는 지점이 있다. Scan, ATPG, stuck-at pattern, transition pattern 이런 건 익숙한데, memory 쪽으로 가는 순간 갑자기 March algorithm, MBIST, fault model 이야기가 쏟아진다. 게다가 시니어 DFT 엔지니어들도 가끔 이런 걸 헷갈린다. “March C-가 정확히 어떤 fault까지 커버하지? 단점이 뭐였더라…” “왜

By Chase Na - Semiconductor Design Engineer
Безглючный тактовый генератор MUX?

russian

Безглючный тактовый генератор MUX?

Одна из самых разочаровывающих ошибок, возникших после вывода полупроводниковой ленты, заключается в следующем:Симуляция функций идеальна, Silicon Bring-up работает большую часть времени, но "иногда" он ведет себя нестабильно. Когда я пытаюсь воспроизвести ее перед профессором, она работает отлично..... Отладочные журналы также слабы из-за отсутствия воспроизводимости. Если вы копнете

By Chase Na - Semiconductor Design Engineer
无闪烁时钟多路复用器?

chinese

无闪烁时钟多路复用器?

在半导体带出之后,最令人沮丧的 bug 之一就是这个:函数仿真完美,Silicon Bring-up 大部分时间正常工作,但"有时 "表现不稳定。当我尝试在教授面前重现它时,它工作正常....。由于缺乏可重复性,调试日志也很模糊。如果你深入挖掘,往往会得出相同的结论: * "定时在某个地方被破坏了。" * 这个 "某个地方 "通常是一个全局控件,如 时钟/重置。 * 具体来说,时钟到 MUX点的非常细的脉冲(故障)。 时钟路径中的故障与数据故障属于不同类型的故障。 另一方面,时钟故障会被触发器感知为"额外时钟边沿",从那时起,一个异常边沿就会扭曲整个系统状态。这就是为什么经典的解决方案是无故障时钟 MUX (GFCM)。 1) 为什么常规多路复用器 (MUX) 中会出现闪烁 最简单的

By Chase Na - Semiconductor Design Engineer
グリッチフリー・クロックMUX?

japanese

グリッチフリー・クロックMUX?

半導体のTape-out後、最も苦痛なバグの一つはこのような形である。 Function simulationも完璧、Silicon Bring-upでもほとんど正常、しかし"たまに"異常動作をする教授の前で再現しようとすると、またうまく動作する ....再現性が低く、デバッグログも薄暗い。 * "どこかでタイミングが崩れた。" * その"どこか"がClock/Resetのようなglobal controlであることが多い。 * 特にClockをMUXに変更するポイントで非常に薄いパルス(Glitch)が飛び出す Clock pathでのGlitchはdata glitchとはレベルが違います。データパスのグリッチは、通常、コンビネーションロジック内で消費されます。 一方、クロックグリッチは、フリップフロップに"追加のクロックエッジ"として認識され、その瞬間から、1回の異常エッジがシステム状態全体を歪めることができます。そこで登場するのが、Glitch-Free Clock MUX(GFCM)です。 1) 一般的なMultiplexer(

By Chase Na - Semiconductor Design Engineer
Glitch-Free Clock MUX란?

korean

Glitch-Free Clock MUX란?

반도체 Tape-out 후 가장 괴로운 버그 중 하나는 이런 형태다. Function simulation도 완벽, Silicon Bring-up에서도 대부분 정상, 그런데 “가끔” 비정상 동작을 한다. 교수님 앞에서 재현하려고 하면, 또 잘 동작한다.... 재현성이 낮아 디버그 로그도 희미하다. 이때 끝까지 파고들면 종종 같은 결론으로 모인다. * “어딘가에서 Timing이 깨졌다.” * 그 “어딘가”가 Clock/Reset 같은

By Chase Na - Semiconductor Design Engineer
Memory Hierarchy & Memory Wall

English

Memory Hierarchy & Memory Wall

Key Takeaway: From 1947’s magnetic core memory to the forthcoming HBM4 and compute-in-memory architectures, advances in semiconductor memory have continuously reshaped computing performance, capacity, and architecture. Understanding detailed memory types—from on-chip SRAM variants to emerging non-volatile memories—is essential for engineering high-performance, cost-effective systems. 1. Fundamental Principles of

By Chase Na - Semiconductor Design Engineer
What is Physical Design Rule Checking (Physical DRC)?

English

What is Physical Design Rule Checking (Physical DRC)?

Physical Design Rule Checking (DRC) is the cornerstone of semiconductor physical verification, ensuring that an integrated circuit’s layout adheres to the foundry’s manufacturing constraints. By automating the validation of geometric and spacing requirements in chip layouts, DRC prevents catastrophic defects—shorts, opens, misalignments—and secures high yields, manufacturability,

By Chase Na - Semiconductor Design Engineer
Why is Interconnect Delay Still Large with Advanced Process Nodes?

English

Why is Interconnect Delay Still Large with Advanced Process Nodes?

The continuous scaling of semiconductor process nodes improves transistor density, but it disproportionately amplifies interconnect parasitics, necessitating a "shift-left" approach where the interconnect effect, particularly resistance, must be considered much earlier and more stringently throughout the design flow. The transition to advanced process nodes signifies a shift from

By Chase Na - Semiconductor Design Engineer
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