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
7.3.1.5.3 PCS Loopback
DP83TC812S-Q1 DP83TC812R-Q1 PCS Loopback with data generator Figure 7-3 PCS Loopback with data generator
DP83TC812S-Q1 DP83TC812R-Q1 PCS Loopback without data generator Figure 7-4 PCS Loopback without data generator

PCS Loopback will loop back data prior to it exiting the PCS and entering the PMA. Data received from the MAC on the transmit path is brought through the digital block within the PHY where it is then routed back to the MAC through the receive path. The DP83TC812 receive PMA circuitry is configured for isolation to prevent contention.

Enable Loopback

Write register 0x0016 = 0x0102

Enable data generator/checker for MAC side

Write register 0x0624 = 0x55BF

Write register 0x0619 = 0x1555

Check incoming data from MAC side

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

Enable data generator/checker for Cable side

Write register 0x0624 = 0x55BF

Write register 0x0619 = 0x0557

Check data for Cable side

  1. Write register 0x0620[1] = 1'b1
  2. Read register 0x620
    1. Bit [7:0] = Number of errors bytes received
    2. Bit [8] = PRBS checker lock status on incoming data (1'b1 indicates lock)
Repeat steps 1 and 2 to continously check error status of incoming data stream.

Other system requirements

Data generate by the internal PRBS will be transmitted over the MDI and the MAC interface.