SNLA423 March   2023 DP83826E

 

  1. 1Trademarks
  2. 2DP83826 Application Overview
  3. 3Troubleshooting the Application
    1. 3.1 Read and Check Register Values
    2. 3.2 Schematic and Layout Checklist
    3. 3.3 Component Checklist
    4. 3.4 Peripheral Pin Checks
      1. 3.4.1 Power Supplies
      2. 3.4.2 Probe the XI Clock
      3. 3.4.3 Probe the RESET_N Signal
      4. 3.4.4 Probe the Strap Pins During Initialization
      5. 3.4.5 Probe the Serial Management Interface Signals (MDC, MDIO)
      6. 3.4.6 Probe the MDI Signals
    5. 3.5 Link Quality Check
    6. 3.6 Built-In Self Test with Various Loopback Modes
    7. 3.7 Debugging MAC Interface
    8. 3.8 Tools and References
      1. 3.8.1 DP83826 Register Access
      2. 3.8.2 Extended Register Access
      3. 3.8.3 Application Note References
  4. 4Conclusion
  5. 5Revision History

3.8.1 DP83826 Register Access

If register access is not readily available in the application, USB-2-MDIO GUI is available from TI and can be used with an MSP430 Launchpad, purchasable through the TI eStore (https://store.ti.com/). The GUI supports reading and writing registers as well as running script files. It can be used with the DP83826 and the other devices in TI's Ethernet portfolio. The USB-2-MDIO User's Guide and GUI are available for download at: http://www.ti.com/tool/usb-2-mdio

Below is an example script that can also be found in the USB-2-MDIO GUI in the Help menu:

// This is how you make a comment. All scripts must start with 'begin' 
begin
// To read a register, all you need to do is put down the 4 digit
// HEX value of the registers (from 0000 to FFFF) 
// Example to read registers 0001, 000A, and 0017 
0001
000A
0017
// To write a register, all you need to do is put down the 4 digit 
// HEX value of the register (from 0000 to FFFF) followed by the 
// HEX you desire to configure the register to (from 0000 to FFFF) 
// Example to write 2100 to register 0000 and
// Example to write 0110 to register 0016 
0000 2100
0016 0110
// You must end the script by adding 'end' once you are finished
end

The Serial Management Interface defined by IEEE 802.3 is a single master bus. The MDC clock is generated by the bus master, typically an Ethernet MAC. To use the USB-2-MDIO GUI, connections must be made directly between the MSP430 Launchpad and the DP83826 MDIO and MDC pins.

  • MSP430 Pin 4.2 → PHY's MDIO Pin
  • MSP420 Pin 4.1 → PHY's MDC Pin