SNLS654C April   2021  – November 2024 DP83TC812R-Q1 , DP83TC812S-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Diagnostic Tool Kit
        1. 7.3.1.1 Signal Quality Indicator
        2. 7.3.1.2 Electrostatic Discharge Sensing
        3. 7.3.1.3 Time Domain Reflectometry
        4. 7.3.1.4 Voltage Sensing
        5. 7.3.1.5 BIST and Loopback Modes
          1. 7.3.1.5.1 Data Generator and Checker
          2. 7.3.1.5.2 xMII Loopback
          3. 7.3.1.5.3 PCS Loopback
          4. 7.3.1.5.4 Digital Loopback
          5. 7.3.1.5.5 Analog Loopback
          6. 7.3.1.5.6 Reverse Loopback
      2. 7.3.2 Compliance Test Modes
        1. 7.3.2.1 Test Mode 1
        2. 7.3.2.2 Test Mode 2
        3. 7.3.2.3 Test Mode 4
        4. 7.3.2.4 Test Mode 5
    4. 7.4 Device Functional Modes
      1. 7.4.1  Power Down
      2. 7.4.2  Reset
      3. 7.4.3  Standby
      4. 7.4.4  Normal
      5. 7.4.5  Sleep Ack
      6. 7.4.6  Sleep Request
      7. 7.4.7  Sleep Fail
      8. 7.4.8  Sleep
      9. 7.4.9  Wake-Up
      10. 7.4.10 TC10 System Example
      11. 7.4.11 Media Dependent Interface
        1. 7.4.11.1 100BASE-T1 Master and 100BASE-T1 Slave Configuration
        2. 7.4.11.2 Auto-Polarity Detection and Correction
        3. 7.4.11.3 Jabber Detection
        4. 7.4.11.4 Interleave Detection
      12. 7.4.12 MAC Interfaces
        1. 7.4.12.1 Media Independent Interface
        2. 7.4.12.2 Reduced Media Independent Interface
        3. 7.4.12.3 Reduced Gigabit Media Independent Interface
        4. 7.4.12.4 Serial Gigabit Media Independent Interface
      13. 7.4.13 Serial Management Interface
        1. 7.4.13.1 Direct Register Access
        2. 7.4.13.2 Extended Register Space Access
        3. 7.4.13.3 Write Operation (No Post Increment)
        4. 7.4.13.4 Read Operation (No Post Increment)
        5. 7.4.13.5 Write Operation (Post Increment)
        6. 7.4.13.6 Read Operation (Post Increment)
    5. 7.5 Programming
      1. 7.5.1 Strap Configuration
      2. 7.5.2 LED Configuration
      3. 7.5.3 PHY Address Configuration
    6. 7.6 Register Maps
      1. 7.6.1 Register Access Summary
      2. 7.6.2 DP83TC812 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information Disclaimer
    2. 8.2 Application Information
    3. 8.3 Typical Applications
      1. 8.3.1 Design Requirements
        1. 8.3.1.1 Physical Medium Attachment
          1. 8.3.1.1.1 Common-Mode Choke Recommendations
      2. 8.3.2 Detailed Design Procedure
      3. 8.3.3 Application Curves
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Signal Traces
        2. 8.5.1.2 Return Path
        3. 8.5.1.3 Metal Pour
        4. 8.5.1.4 PCB Layer Stacking
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Community Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
7.3.1.5.2 xMII Loopback
DP83TC812S-Q1 DP83TC812R-Q1 xMII Loopback Without Data Generator Figure 7-2 xMII Loopback Without Data Generator

xMII Loopback is the shallowest loop through the PHY. It is a useful test mode to validate communications between the MAC and the PHY. When in xMII Loopback, data transmitted from a connected MAC on the TX path is internally looped back in the DP83TC812 to the RX pins where it can be checked by the MAC. There is no link indication when in xMII loopback.

Enable Loopback

Write register 0x0000 = 0x6100

Enable data generator/checker for MAC side

Data will be generated externally on the MAC TX pins.

Use the following register settings to enable checker depending on the MAC interface mode.

  • For RGMII, write register 0x0619 = 0x1004
  • For SGMII, write register 0x0619 = 0x1114
  • For RMII, write register 0x0619 = 0x1224
  • For MII, write register 0x0619 = 0x1334

Check incoming data from MAC side

Data can be verified at MAC interface RX pins.

Data can also be checked internally by reading registers 0x063C, 0x063D, 0x063E

Enable data generator/checker for Cable side

Not applicable as data will be generated externally on the MAC interface TX pins.

Check data for Cable side

Not applicable as PRBS stream checker works with only internal PRBS generator.

Other system requirements

Generated data will be going to cable side.