SLUUDO2 September   2026 AM2611 , AM2612 , AM2612-Q1 , AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1 , AM263P2 , AM263P2-Q1 , AM263P4 , AM263P4-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Acronyms
  5. 2Introduction
  6. 3Introduction to CPSWSS and ENET-LLD
    1. 3.1 Hardware
    2. 3.2 Software
    3. 3.3 Application Software
      1. 3.3.1 Board and Peripherals Initialization (SYSCFG)
      2. 3.3.2 CPSW Configuration (ENET-LLD)
      3. 3.3.3 Operating System (FreeRTOS or NoRTOS)
      4. 3.3.4 Middleware Stack (LwIP, Arm® Mbed™ Platform TLS, TSN)
      5. 3.3.5 Application Layer
  7. 4Debugging Hardware and Software
    1. 4.1 Hardware Debugging
      1. 4.1.1 Schematic Review Checklist
        1. 4.1.1.1 Management Data Input/Output (MDIO and MDC)
        2. 4.1.1.2 RGMII Interface
      2. 4.1.2 PHY Debug
        1. 4.1.2.1 PHY Bootstrap Settings
        2. 4.1.2.2 Trace Length
        3. 4.1.2.3 Clock Configuration
        4. 4.1.2.4 Mode Settings
        5. 4.1.2.5 IO MUX and SW Switch Settings
        6. 4.1.2.6 PHY Troubleshooting Guides
        7. 4.1.2.7 Custom Pin MUX Settings
      3. 4.1.3 Test Setup
      4. 4.1.4 Software Debugging
        1. 4.1.4.1 Using GEL Scripts in CCS
          1. 4.1.4.1.1 Statistics Using GEL Scripts
          2. 4.1.4.1.2 Statistics Using Expressions
      5. 4.1.5 Debugging Custom Ethernet Software
        1. 4.1.5.1 Debugging Initialization Sequence
        2. 4.1.5.2 PHY Debugging
        3. 4.1.5.3 MAC Port Debugging
        4. 4.1.5.4 TX Path Debugging
        5. 4.1.5.5 Systematic Debugging Checklist
          1. 4.1.5.5.1 RX Path Debugging
          2. 4.1.5.5.2 Multicast or Broadcast Does Not Work, But Unicast Works
    2. 4.2 Custom Hardware Bring-Up Process
      1. 4.2.1 Example 1: CPSW PHY Loopback
        1. 4.2.1.1 Failure: PHY Not Detected or MDIO Bus Not Alive
        2. 4.2.1.2 Failure: TX Packets Transmitted But RX Count = 0
      2. 4.2.2 Example 2: CPSW MAC Loopback Example
        1. 4.2.2.1 Failure: MAC Loopback Initialization Fails
        2. 4.2.2.2 Failure: TX Packets Increase But RX = 0
        3. 4.2.2.3 Failure: Nonzero Error Counters
      3. 4.2.3 Example 3: Enet_Layer2_CPSW and Enet_Layer2_cpsw_switch
        1. 4.2.3.1 Hardware Setup
        2. 4.2.3.2 Failure: Link Never Comes UP
        3. 4.2.3.3 Failure: Link is Up But No Frames Are Received or Transmitted
        4. 4.2.3.4 Failure: RX and TX Counters Increase But Error Rates Are High
      4. 4.2.4 Example 4: Enet_lwip_cpsw_example
        1. 4.2.4.1 Failure: Link Never Comes Up
        2. 4.2.4.2 Failure: Links Up But No IP Address Is Assigned
        3. 4.2.4.3 Failure: Ping Fails Despite Link and IP Address
    3. 4.3 Debugging Packet Forwarding Issues (ALE and Statistics)
      1. 4.3.1 CPSW Statistics Architecture
        1. 4.3.1.1 What Each Block Measures
        2. 4.3.1.2 Counter Reference Tables
          1. 4.3.1.2.1 MAC Port – RX Counters
          2. 4.3.1.2.2 MAC Port – TX Counters
          3. 4.3.1.2.3 MAC Port and Host Port – ALE and FIFO Drop Counters
          4. 4.3.1.2.4 Host Port – ALE Flood and Overrun Counters
          5. 4.3.1.2.5 MAC Port RX Issues
          6. 4.3.1.2.6 MAC Port TX Issues
          7. 4.3.1.2.7 Host Port RX Issues
          8. 4.3.1.2.8 Host Port TX Issues
    4. 4.4 Custom Board Enablement in SYSCFG
    5. 4.5 LwIP Debug Guide
      1. 4.5.1 LwIP Stack Configuration
      2. 4.5.2 lwip_stats
  8. 5Conclusion
  9. 6References

4.3 Debugging Packet Forwarding Issues (ALE and Statistics)

Hardware statistics counters provide the fastest path to isolating packet forwarding failures on the CPSW. For pinpointing the root cause, the CPSW STATS can be leveraged to find where the issues lie, whether in the ALE, MAC port, or host port configurations. STATS is a functional block in CPSW.

There are two ways to get the statistical values:

  • Use the GEL scripts to obtain the CPSW statistics. In this method all nonzero CPSW statistics can be obtained.
  • Using the expression window. This expression can be pasted in the Watch Expressions window to view the CPSW statistics.

(CSL_Xge_cpswRegs *) (gEnetSoc_cpsw3g.enetPer.virtAddr)

The key principle is that the statistics counter signature reveals the failure mode.

Table 4-12 lists some of the common issues that can be uncovered using CPSW statistics.

Table 4-12 CPSW Statistical Summary
Issue Symptom Primary Counters to Examine
The frame counts look correct but data is corrupted rxCrcErrors, rxAlignCodeErrors, and rxOversizedFrames
Intermittent RX loss under high load rxBottomOfFifoDrop, rxTopOfFifoDrop, and aleOverrunDrop
The application sends Ethernet packets but nothing appears on the wire portMaskDrop, txSofOverrun, and MAC txGoodFrames
Packets arrive at the wire but the application receives nothing portMaskDrop, aleDrop, and rxBottomOfFifoDrop
Traffic tagged as VLAN silently drops aleVidIngressDrop and aleBlockDrop
Broadcast and multicast storm—throughput degrades aleRateLimitDrop, aleUnknownBcast, and aleUnknownMcast