SNLS779A July   2025  – November 2025 DP83TC815-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
    1. 5.1 Pin Power Domain
    2. 5.2 Pin States
    3. 5.3 Pin Multiplexing
  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 IEEE802.1AS Features
        1. 7.3.1.1 PTP Clock Configuration
          1. 7.3.1.1.1 PTP Reference Clock
          2. 7.3.1.1.2 PTP Synchronized Clock (Wall Clock)
            1. 7.3.1.1.2.1 PTP Time Read or Write
            2. 7.3.1.1.2.2 PTP Clock Initialization
            3. 7.3.1.1.2.3 PTP Clock Adjustment
            4. 7.3.1.1.2.4 PTP Clock Output
              1. 7.3.1.1.2.4.1 One Pulse Per Second (PPS) Output
          3. 7.3.1.1.3 PTP Time Registers
        2. 7.3.1.2 Packet Timestamps
          1. 7.3.1.2.1 Transmit (Egress) Packet Parser and Timestamp
          2. 7.3.1.2.2 Receive (ingress) Packet Parser and Timestamp
          3. 7.3.1.2.3 PTP Transmit and Receive Timestamp Registers
        3. 7.3.1.3 Event Triggering and Timestamping
          1. 7.3.1.3.1 Event Triggering (Output)
            1. 7.3.1.3.1.1 Trigger Initialization
          2. 7.3.1.3.2 Event Timestamp (Input)
            1. 7.3.1.3.2.1 Timestamp Storage and Reading
          3. 7.3.1.3.3 Event Capture and Output Trigger Registers
        4. 7.3.1.4 PTP Interrupts
        5. 7.3.1.5 PTP I/O Configuration
      2. 7.3.2 TC10 Sleep Wake-up
        1. 7.3.2.1 Functions of the PHY for TC10 Support
          1. 7.3.2.1.1 Transition from Sleep to Wake-up Mode
            1. 7.3.2.1.1.1 Local Wake Detection
            2. 7.3.2.1.1.2 WUP Transmission and Reception
          2. 7.3.2.1.2 Wake Forwarding
          3. 7.3.2.1.3 Transition to Sleep - Sleep Negotiation
            1. 7.3.2.1.3.1 Sleep Ack
            2. 7.3.2.1.3.2 Sleep Request
            3. 7.3.2.1.3.3 Sleep Silent
            4. 7.3.2.1.3.4 Sleep Fail
            5. 7.3.2.1.3.5 Sleep
            6. 7.3.2.1.3.6 Force Sleep
        2. 7.3.2.2 Power Supply Networks for Sleep Applications
        3. 7.3.2.3 Configuration for Non-TC10 Applications
        4. 7.3.2.4 Miscellaneous Sleep Features
        5. 7.3.2.5 Fast Wake-up
      3. 7.3.3 PPM Monitor
      4. 7.3.4 Clock Dithering
      5. 7.3.5 Output Slew Control
      6. 7.3.6 Diagnostic Tool Kit
        1. 7.3.6.1 Signal Quality Indicator
        2. 7.3.6.2 Electrostatic Discharge Sensing
        3. 7.3.6.3 Time Domain Reflectometry
        4. 7.3.6.4 Voltage Sensing
        5. 7.3.6.5 Temperature Sensing
      7. 7.3.7 BIST and Loopback Modes
        1. 7.3.7.1 Data Generator and Checker
        2. 7.3.7.2 xMII Loopback
        3. 7.3.7.3 PCS Loopback
        4. 7.3.7.4 Digital Loopback
        5. 7.3.7.5 Analog Loopback
        6. 7.3.7.6 Reverse Loopback
      8. 7.3.8 Compliance Test Modes
        1. 7.3.8.1 Test Mode 1
        2. 7.3.8.2 Test Mode 2
        3. 7.3.8.3 Test Mode 4
        4. 7.3.8.4 Test Mode 5
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Modes
        1. 7.4.1.1 Power Down
        2. 7.4.1.2 Reset
        3. 7.4.1.3 Standby
        4. 7.4.1.4 Normal
        5. 7.4.1.5 Sleep
      2. 7.4.2 Media Dependent Interface
        1. 7.4.2.1 100BASE-T1 Leader and 100BASE-T1 Follower Configuration
        2. 7.4.2.2 Auto-Polarity Detection and Correction
        3. 7.4.2.3 Jabber Detection
        4. 7.4.2.4 Interleave Detection
      3. 7.4.3 MAC Interfaces
        1. 7.4.3.1 Media Independent Interface
        2. 7.4.3.2 Reduced Media Independent Interface
        3. 7.4.3.3 Reduced Gigabit Media Independent Interface
        4. 7.4.3.4 Serial Gigabit Media Independent Interface
      4. 7.4.4 Serial Management Interface
        1. 7.4.4.1 Extended Register Space Access
        2. 7.4.4.2 Write Operation (No Post Increment)
        3. 7.4.4.3 Read Operation (No Post Increment)
        4. 7.4.4.4 Write Operation (Post Increment)
        5. 7.4.4.5 Read Operation (Post Increment)
    5. 7.5 Programming
      1. 7.5.1 Strap Configuration
        1. 7.5.1.1 LED Configuration
  9. 8 Register Maps
    1. 8.1 Register Access Summary
    2. 8.2 DP83TC815 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Physical Medium Attachment
          1. 9.2.1.1.1 Common-Mode Choke Recommendations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Signal Traces
        2. 9.4.1.2 Return Path
        3. 9.4.1.3 Metal Pour
        4. 9.4.1.4 PCB Layer Stacking
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
7.3.1.1.2 PTP Synchronized Clock (Wall Clock)

The PTP time clock in DP83TC815-Q1 is a readable or writable time source for all IEEE802.1AS PTP related functions. PTP clock is a high accuracy oscillator and a counter that represents time in seconds and nanoseconds.

The clock consists of Seconds (32–bit field) and Nanoseconds (30–bit field). When the nanoseconds counter reaches 1 x 109, the nanoseconds counter reverts to zero and the seconds counter increments by 1. Additionally, a Fractional Nanoseconds (sub nanosecond - units of 2-32 ns) counter for time adjustment is available. PTP_RATE_DIR controls whether the device operates at a higher or lower frequency than the reference clock. The clock counter increment per cycle varies depending on the reference clock used and is equal to the period (in ns) corresponding to the PTP reference clock. A Frac PLL is used to generate non-integer synchronized clock output. Use of Frac PLL eliminates need for external VCXO.

DP83TC815-Q1 PTP Timestamping - ClockFigure 7-2 PTP Timestamping - Clock

The clock does not support negative time values. If negative time is required in the system, the host software has to make conversions from the PHY clock time to actual time.

The clock also does not support the upper 16-bits of the seconds field as defined by the specification (Version 2 specifies a 48-bit seconds field). If the upper 16-bits value is required to be greater than 0, it has to be handled by host software. The rollover of the seconds field only occurs every 136 years, minimizing burden to host software.