SNLA364C March   2021  – June 2022 DP83TD510E

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
  4. 2 1-V and 2.4-V p2p Mode Scripts
  5. 3 Time-Domain Reflectometry
    1. 3.1 TDR Application Startup
      1. 3.1.1 TDR_CFG (Address = 0x001E) [Reset = 0x0000]
      2. 3.1.2 TDR_Fault_Status (Address = 0x030C) [Reset = 0x0000]
    2. 3.2 TDR Test Procedure
  6. 4 Active Link Cable Diagnostics
    1. 4.1 ALCD Application Startup
    2. 4.2 ALCD Test Procedure
      1. 4.2.1 Cable Calibration
      2. 4.2.2 Cable Quality Measurement
  7. 5 Signal Quality Indicator
    1. 5.1 SQI Application Startup
      1. 5.1.1 MSE Detection (Address = 0x0A85 ) [Reset = 0x0000]
    2. 5.2 SQI Test Procedure
  8. 6 Cable Diagnostics Summary
  9. 7 Loopback Modes
    1. 7.1 BISCR (Address = 0x0016) [Reset = 0x0100]
  10. 8 Pseudo-Random Bit Sequence Functions
    1. 8.1 PRBS_CFG_1 (Address = 0x0119) [Reset = 0x0574]
    2. 8.2 PRBS_STATUS_4 (Address = 0x011F) [Reset = 0x0000]
  11. 9 USB to MDIO Procedure
  12. 10IEEE 802.3cg PMA Compliance
  13. 11Revision History

3.2 TDR Test Procedure

Note: Scripts provided in this application note follow the format of the USB-2-MDIO tool. Example: 0301 2404 The first 4-digit value is register address to read or write. The second 4-digit value is register data to write into the address.

To configure the TDR circuitry within the PHY, the following registers must be set:

begin
001F 8000
0200 0000
0834 4000
0301 2403
0303 043E
030E 2520
001F 4000
end

Start TDR manually:

begin
//Soft Reset
001F 4000

//Start TDR measurement
001E 8000
end

Check the completion status and results of TDR measurement:

begin
//Soft Reset
001F 4000

// Error Checking
001E      //Observe bits [1:0] for completion status, bit [0] must be 1b for TDR status to be valid

//Read TDR result
030C     //Observe bits [11:10] for fault detection and [9:0] for fault location
end

The location of the fault is measured in meters and can be found by converting bits 0x030C[9:0] to decimal format.

Note: A High Attenuation cable might need a different TDR script. A Register 030C reading of 0000 indicates that the cable is a high attenuation cable.