TIDUFG8 December   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Terminology
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Industrial Protocol Fragmentation
      2. 2.2.2 Real-Time Performance and Determinism
      3. 2.2.3 Component Cost and PCB Space Constraints
      4. 2.2.4 Protocol Certification and Software Maintenance
    3. 2.3 Highlighted Products
      1. 2.3.1 AM2612 Microcontroller
      2. 2.3.2 DP83826A Ethernet PHY
      3. 2.3.3 TPS65214 Power Management IC
      4. 2.3.4 LMK3C0105 Clock Generator
  9. 3System Design Theory
    1. 3.1 Key Requirements and Design Considerations
      1. 3.1.1 Operating Modes
    2. 3.2 Software Architecture and Boot Flow
    3. 3.3 Industrial Communication Subsystem (ICSS)
    4. 3.4 Clocking and Synchronization
    5. 3.5 Power Supply
      1. 3.5.1 Multiprotocol Industrial Ethernet Subsystem Power Supply
      2. 3.5.2 System Power Supply
    6. 3.6 Real-Time Ethernet Media Independent Interface (MII)
      1. 3.6.1 SYNC/LATCH Pins for Real-Time Tasks
      2. 3.6.2 Layout Considerations
        1. 3.6.2.1 Layout Guidelines
      3. 3.6.3 EMI and EMC Considerations
      4. 3.6.4 AM2612 Bootstrap Interface
      5. 3.6.5 RJ45 Ethernet Interface
      6. 3.6.6 Industrial User Interface
      7. 3.6.7 Programming and Debugging Options
      8. 3.6.8 USB 2.0 Interface
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5.     Trademarks
  11. 5About the Author

2.2.2 Real-Time Performance and Determinism

Industrial Ethernet protocols impose different timing constraints for cycle times, jitter, and synchronization accuracy. EtherCAT and PROFINET IRT require sub-microsecond synchronization. EtherNet/IP and Modbus TCP use standard TCP/IP communication but often need to coexist with deterministic real-time traffic.

Challenge: General-purpose microcontrollers and Linux-based processors often cannot provide deterministic real-time performance under varying CPU load conditions.

Solution: The AM261x integrates a dedicated PRU-based Industrial Communication Subsystem (ICSS) that provides deterministic, low-latency response independent of the host CPU workload. This design enables precise real-time communication for all supported industrial Ethernet standards.