SDAA067 August   2025 DP83826AE , DP83826AI , DP83826E , DP83826I

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Difference Between DP83826x and DP83826Ax
    1. 2.1 Fast Link-Drop (FLD) Strap Configuration
      1. 2.1.1 Basic Mode
      2. 2.1.2 Enhanced Mode
    2. 2.2 EMC Performance
  6. 3Summary
  7. 4References

2.1.2 Enhanced Mode

Table 2-2 and Figure 2-1 list the DP83826x FLD detection mode configuration. Note when Strap7 = High, Strap1 = High/Low, and Strap 8 = High/Low, the MLT3 Error Count is disabled.

Table 2-2 DP83826x FLD Detection Modes by Bootstrap Configuration
Strap Configuration RX Error Count MLT3 Error Count Low SNR Threshold Signal/Energy Loss Descrambler Link Loss
(Default)
Strap7 = LOW
Strap1 = X
Strap8 = X		 Disabled Disabled Disabled Disabled Disabled
Strap7 = HIGH
Strap1 = HIGH
Strap8 = LOW		 Enabled Enabled Enabled Enabled
Strap7 = HIGH
Strap1 = LOW
Strap8 = LOW		 Enabled Disabled Enabled Disabled
Strap7 = HIGH
Strap1 = LOW
Strap8 = HIGH		 Enabled Disabled Disabled Disabled
DP83826x Bootstrap Configurations Flowchart Figure 2-1 DP83826x Bootstrap Configurations Flowchart

Table 2-3 and Figure 2-2 list the DP83826Ax FLD Detection Mode configuration. Note under the same strap configuration, the MLT3 Error Count is enabled. For DP83826x and DP83826Ax, the RX error count is enabled in both cases. With the RX Error being a superset of MLT-3 Error, the superset is triggered before MLT-3 error. So even though there is a configuration difference in the MLT-3 error count, there is no behavioral difference between DP83826x and DP83826Ax.

Table 2-3 DP83826Ax FLD Detection Modes by BootStrap Configuration
FLD Strap Option Strap Configuration RX Error Count(1) MLT3 Error Count Low SNR Threshold Signal/Energy Loss(1)(2) Descrambler Link Loss
1 Strap1 = X
Strap8 = X
Strap11 = X		 Disabled Disabled Disabled Disabled Disabled
2 Strap7 = HIGH
Strap1 = HIGH
Strap8 = LOW
Strap11 = LOW		 Enabled Enabled Enabled Enabled Enabled
3 (3) Strap7 = HIGH
Strap1= LOW
Strap8= LOW
Strap11 = LOW		 Enabled Enabled Disabled Enabled Disabled
4(3) Strap7 = HIGH
Strap1 = LOW
Strap8 = HIGH
Strap11 = LOW		 Enabled Enabled Disabled Disabled Disabled
5(3) Strap7 = HIGH
Strap1 = LOW
Strap8 = HIGH
Strap11 = HIGH		 Disabled Disabled Disabled Enabled Disabled
6 Strap7 = HIGH
Strap1 = HIGH
Strap8 = LOW
Strap11 = HIGH		 Disabled Disabled Enabled Enabled Enabled
(1) Enabling RX_ERROR count and Signal/Engery Loss provides robust FLD operation
(2) Enabling signal and energy loss provides best immunity performance
(3) Recommended FLD enabled strap setting
DP83826Ax Bootstrap Configuration Flowchart Figure 2-2 DP83826Ax Bootstrap Configuration Flowchart

For best EMC performance, TI recommends enabling the signal and energy loss FLD mode.

For both DP83826x and DP83826Ax, additional configuration can be programmed using the Control Register 3 (CR3, register address 0x000B). Bits[3:0] and bit[10] allow for various FLD conditions to be enabled.