Datasheet

www.national.com 12

DP83848T

AN0 (LED_LINK) S, O, PU 22 This input pin controls the advertised operating mode of the

DP83848T according to the following table. The value on this pin

is set by connecting it to GND (0) or V

(1) through 2.2 kΩ resis-

tors. This pin should NEVER be connected directly to GND or

VCC.

The value set at this input is latched into the DP83848T at Hard-

ware-Reset.

The float/pull-down status of this pin is latched into the Basic

Mode Control Register and the Auto_Negotiation Advertisement

The default is 1 since this pin has an internal pull-up.

MII_MODE (RX_DV) S, O, PD 32 MII MODE SELECT: This strapping option determines the oper-

ating mode of the MAC Data Interface. Default operation (No pull-

up) will enable normal MII Mode of operation. Strapping

MII_MODE high will cause the device to be in RMII mode of oper-

ation. Since the pin includes an internal pull-down, the default val-

ue is 0.

The following table details the configuration:

LED_CFG (CRS/CRS_DV) S, O, PU 33 LED CONFIGURATION: This strapping option determines the

mode of operation of the LED pins. Default is Mode 1. Mode 1 and

Mode 2 can be controlled via the strap option. All modes are con-

figurable via register access.

SeeTable 3 for LED Mode Selection.

MDIX_EN (RX_ER) S, O, PU 34 MDIX ENABLE: Default is to enable MDIX. This strapping option

disables Auto-MDIX. An external pull-down will disable Auto-

MDIX mode.

Signal Name Type Pin # Description

AN0 Advertised Mode

0 10BASE-T Half-Duplex

100BASE-TX, Half-Duplex

1 10BASE-T, Half/Full-Duplex

100BASE-TX, Half/Full-Duplex

MII_MODE MAC Interface Mode

0 MII Mode

1 RMII Mode