SNLA334 june   2023 DP83867CR , DP83867CS , DP83867E , DP83867IR , DP83867IS , DP83869HM

 

  1.   1
  2.   DP83867 and DP83869 TDR
  3.   Trademarks
  4. 1Time Domain Reflectometry
    1. 1.1 Example Connections
      1. 1.1.1 Open Circuit Cable
      2. 1.1.2 Short Circuit Cable
  5. 2DP83867 and DP83869 TDR Implementation
    1. 2.1 TDR Configuration
    2. 2.2 TDR Algorithm
      1. 2.2.1 TDR Algorithm Example Flow
      2. 2.2.2 TDR Algorithm Matlab Example
  6. 3Summary
  7. 4References

2.1 TDR Configuration

To run TDR manually, link must be down before register configuration. To use the TDR feature, follow these steps:

  1. Configure the registers shown in the Table 2-1. To see how to configure the extended registers, view the DP83867 or DP83869 data sheets.
    Table 2-1 TDR Register Writes
    Register Address Value
    0x0189 0x0000
    0x0186 0x294A
    0x0187 0x0A9B
    0x001E 0x0003
  2. After running the previous configuration, check that 0x001E[1] = 1 to confirm TDR is successfully completed. Then, read the following extended registers:
    Table 2-2 TDR Register Results
    Registers
    0x0190
    0x0191
    0x0192
    0x019a
    0x019b
    0x019c
    0x01a5
  3. See the next section, TDR Algorithm, for how to process the data collected from the registers to determine the cable fault type and location.