MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR® Technology in a Small Footprint

Datasheet

4.10nINTSEL Strapping and LED Polarity Selection

The nINT, TXER, and TXD4 functions share a common pin. There are two functional modes for this pin, the TXER/TXD4 mode and nINT (interrupt) mode.

The nINTSEL pin is shared with the LED2 pin. The LED2 output will automatically change polarity based on the presence of an external pull-down resistor. If the LED pin is pulled high (by the internal pull-up resistor) to select a logical high for nINTSEL, then the LED output will be active low. If the LED pin is pulled low by an external pull-down resistor to select a logical low nINTSEL, the LED output will then be an active high output.

To set nINTSEL without LEDs, float the pin to set nINTSEL high or pull-down the pin with an external resistor to GND to set nINTSEL low. See Figure 4.5.

The LED2/nINTSEL pin is latched on the rising edge of the nRST. The default setting is to float the pin high for nINT mode.

nINTSEL = 1

nINTSEL = 0

LED output = active low

LED output = active high

VDD2A

LED2/nINTSEL

10K

~270 ohms

~270 ohms

LED2/nINTSEL

Figure 4.5 nINTSEL Strapping on LED2

4.11REGOFF and LED Polarity Selection

The REGOFF configuration pin is shared with the LED1 pin. The LED1 output will automatically change polarity based on the presence of an external pull-up resistor. If the LED pin is pulled high to VDD2A by an external pull-up resistor to select a logical high for REGOFF, then the LED output will be active low. If the LED pin is pulled low by the internal pull-down resistor to select a logical low for REGOFF, the LED output will then be an active high output.

To set REGOFF without LEDs, pull-up the pin with an external resistor to VDDIO to disable the regulator. See Figure 4.6.

Revision 1.0 (04-15-09)

32

SMSC LAN8710/LAN8710i

 

DATASHEET