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Course contents

  • How to Use This Course
  • Protocol Metrics Reference
  • Protocols Glossary
  • Reading Path
  • Protocol Fundamentals25
  • AMBA Family (APB / AHB / AXI)17
  • Coherence Fabrics (ACE / CHI)17
  • Memory Interfaces (DDR / LPDDR / HBM)17
  • PCIe & CXL17
  • Embedded Peripherals (I2C / SPI / UART)17
  • High-Speed I/O (USB / Ethernet / MIPI)17
  • Protocol Verification & Compliance21
  • Protocols Interview Prep5
  • Interface Protocols Cheatsheet
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←Bus Protocols
  1. Topics
  2. Bus Protocols
  3. Interface Protocols Cheatsheet
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    Interface ProtocolsAll levels

    Interface Protocols Cheatsheet

    Dense reference for protocol debug, integration, and interview answers.

    Debug order

    Context → boundaries → first observed divergence → discriminator → regression.

    Interface

    Evidence to keep together

    AMBA

    Accepted AR/AW/W/R/B items, source/ID context, bursts and responses

    ACE / CHI

    Line state, home/snoop obligations, shareability and retry context

    DDR

    Controller/PHY configuration, training, command timing, refresh and errors

    PCIe / CXL

    Packet/Tag context, link state, credits, mappings and attach capabilities

    Peripheral

    Reset state, register contract, interrupt source and DMA ownership

    Verification

    Monitor events, independent expectations, assertions, coverage and requirement evidence

    Keep completion boundaries separate

    Observation

    What remains to establish

    Sequence item submitted

    Actual hardware acceptance and result.

    AXI AW or W accepted

    Other required parts, target work and response obligations.

    APB SETUP or waiting ACCESS

    The completing ACCESS edge and response status.

    PCIe link ACK

    The Memory Read's transaction-level Completion/data.

    IRQ controller acknowledged

    The peripheral source's documented deassertion and event handling.

    Harness PASS

    Whether the result is a clean control or expected mutation rejection, and what remains unverified.

    Shared model and trace conventions

    Definitions with worked-lesson links

    Questions before proposing a fix

    1. Which transaction failed first?

    2. Which layer owns forward progress?

    3. Is the observed behavior illegal or merely unexpected?

    4. Which metric demonstrates the stated product impact?

    5. Which evidence distinguishes the leading root-cause hypotheses?

    6. Which regression protects compatibility?

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    See also

    • How to Use This Course
    • Protocol Metrics Reference
    • Protocols Glossary