SPRADH9 June   2024 AM6442

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Abbreviations
  5. 2Introduction
    1. 2.1 Peripheral Component Interconnect Express
      1. 2.1.1 Components of PCIe Communication
        1. 2.1.1.1 Root Complex
        2. 2.1.1.2 Repeater
        3. 2.1.1.3 Endpoints
      2. 2.1.2 Signaling
        1. 2.1.2.1 PERST
        2. 2.1.2.2 WAKE and CLKREQ
        3. 2.1.2.3 REFCLK
      3. 2.1.3 PCIe Common Usage
      4. 2.1.4 PCIe Aggregate Throughput
    2. 2.2 PCIe Features on AM64x and AM243x
  6. 3X86 as RC and AM64x as EP
    1. 3.1 Hardware Environment
    2. 3.2 Software Environment
      1. 3.2.1 Building Application
      2. 3.2.2 Usage
  7. 4Test Setup
    1. 4.1 Common Setup for LINUX and WIN
    2. 4.2 Linux Driver (VFIO)
      1. 4.2.1 Prerequisites
      2. 4.2.2 Building
      3. 4.2.3 Deploying
    3. 4.3 Test Application Usage
    4. 4.4 Setup Steps for LINUX PC
      1. 4.4.1 UART Console Output
    5. 4.5 MSI Example
    6. 4.6 Setup Steps for WINDOWS PC
      1. 4.6.1 Prerequisites
      2. 4.6.2 Building
      3. 4.6.3 Deploying
  8. 5PCIe Test Specification
    1. 5.1  Identification and Configuration Functionalities
      1. 5.1.1 Test Case
    2. 5.2  Reference Clock Functionalities
    3. 5.3  Inbound ATU and BAR Functionalities
    4. 5.4  Outbound ATU Functionalities
    5. 5.5  MSI Functionality
    6. 5.6  Downstream Interrupt Functionality
    7. 5.7  Device Power Management State Functionality
    8. 5.8  Function Level Reset Mechanism
    9. 5.9  Legacy Interrupt Mechanism
    10. 5.10 MSI-X Capability
    11. 5.11 Hot Reset Mechanism
  9. 6Windows Example Driver Verification
  10. 7References

2.1.2.2 WAKE and CLKREQ

WAKE and CLKREQ signals are both used for transitioning to and from low power states. WAKE signal is an active-low signal that is used to return the PCIe interface to an active state when in a low-power state. CLKREQ signal is also an active-low signal and is used to request the reference clock. In Figure 2-2, these are referred as WAKE# and CLKREQ#, respectively.