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

7.4.12.4 Serial Gigabit Media Independent Interface

The Serial Gigabit Media Independent Interface (SGMII) provides a means for data transfer between MAC and PHY with significantly less signal pins (4 pins) compared to MII (14 pins), RMII (7 pins) or RGMII (12 pins). SGMII uses low-voltage differential signaling (LVDS) to reduce emissions and improve signal quality.

The DP83TC812 SGMII is capable of operating in 4-wire. SGMII is configurable through hardware bootstraps. In 4-wire operation, two differential pairs are used to transmit and receive data. Clock and data recovery are performed in the MAC and in the PHY.

Because the DP83TC812 operates at 100-Mbps, the 1.25-Gbps rate of the SGMII is excessive. The SGMII specification allows for 100-Mbps operation by replicating each byte within a frame 10 times. Frame elongation takes place above the IEEE 802.3 PCS layer, which prevents the start-of-frame delimiter from appearing more than once.

Because the DP83TC812 only supports 100-Mbps speed, SGMII Auto-Negotitation can be disabled by setting bit[0] = 0b0 in the Register 0x608.

The SGMII signals are summarized in Table 7-15.

Table 7-15 SGMII Signals
FUNCTIONPINS
Data SignalsTX_M, TX_P
RX_M, RX_P
DP83TC812S-Q1 DP83TC812R-Q1 SGMII Connections Figure 7-17 SGMII Connections