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

5.2 Reference Clock Functionalities

Test

Description:

Test to verify if external reference clock can be configured on TMDS243EVM PCIe EP and if PCIe EP works correctly with external reference clock.

Execution:

  1. Check if the following setting is configured on Sysconfig:
    1. Reference Clock Mode: External Reference Clock, no SSC
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  2. Verify if Common Clock and Slot Clock mechanisms are enabled as shown in the following figure.
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Test

Description:

Test to verify if internal reference clock configuration of AM243X/AM64X can be used with enabled output and SSC configuration.

Execution:

  1. Remove PCIe cable PCIE_FLEX_CLK from TMDS243EVM PCIe EP
    Note:

    This is important since having two driving PCIe reference clock sources from EP and RC can damage the hardware.

  2. Configure the following setting via Sysconfig:
    1. Internal Reference Clock, no SSC, Output enabled.
  3. Measure the PCIe reference clock spectrum on PCIe connector. Since SCC is disabled, the measured spectrum shows a single frequency above the noise level at 100MHz as shown in the following image.
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  4. Configure the following setting via Sysconfig:
    1. Internal Reference Clock, with SSC, Output enabled.
  5. Since SCC is enabled, the measured spectrum can be spread one around 100MHz as shown in the following image.
    AM6442

We probe REFCLK+ and respective GROUND pins to get waveform on oscilloscope

https://en.wikipedia.org/wiki/PCI_Express

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