Configurations Options; Strap Options - Texas Instruments DP83825EVM User Manual

Configurations Options

3 Configurations Options

3.1 Strap Options

All straps are only two level straps in DP83825. DP83825 contains internal pull down resistors on the strap pins.
The EVM takes advantage of this feature and has only pull up resistors on the board. When DP83825 strap
pins are using internal pull down the corresponding pin is strapped to '0' and when the strap pin has an external
pull up resistor connected, the corresponding pin is strapped to '1'. Resistors R43, R45, R48, R50, needs to be
installed to be used as pull up strap connectors (can be found on the back side of the board). When any strap
pin needs to be strapped to '0' on the EVM, disconnect the corresponding resistor. When a strap pin needs to be
strapped to '1', populate the corresponding resistor.
STRAP VALUE
Resistor Pull Up
Resistor Pull Down
The LED_0 pin also has a strap. Because LED pins have automatic polarity, separate LEDs are used on the
EVM depending on LED_0 pin being strapped high or low. In position 1-2 LED_0 is pulled low (0) and in position
2-3 LED_0 is pulled high (1).
PIN NAME STRAP NAME
LED_0 ANEG_DIS
RX_D1 RMII_MAS
RX_D0 PHY_AD[0]
CRS_DV PHY_AD[1]
RX_ER AMDIX_DIS
6 DP83825 Evaluation Module
Table 3-1. Strap Value
'1'
2.49 kΩ
Open
Figure 3-1. LED_0 Strap
Table 3-2. Strap Options Table
PIN NO DEFAULT
4 0
17 0
18 0
20 0
22 0
Copyright © 2023 Texas Instruments Incorporated
2.49 kΩ (optional)
VALUE DESCRIPTION
0 Enable Auto negotiation
1 Disable Auto negotiation
0 RMII Master Mode
1 RMII Slave Mode
0 PHY_AD[0] = 0
1 PHY_AD[0] = 1
0 PHY_AD[1] = 0
1 PHY_AD[1] = 1
0 AMDIX Enabled
1 AMDIX Disabled
SNLU239A – DECEMBER 2018 – REVISED DECEMBER 2023
www.ti.com
'0'
Open
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