CS8952 datasheet(70/82 Pages) CIRRUS

70 / 82 page

CS8952

CrystalLAN™ 100BASE-X and 10BASE-T Transceiver

In order to conform with Annex 22B of the IEEE 802.3u specification, the MII_DRV pin should be pulled

high during power-up or reset, and the RX_CLK pin should have an external 33

Ω series resistor. For

systems not required to drive external connectors and cables as described in the IEEE802.3u

specification, the external series resistor may not be necessary.

RX_DV/MII_DRV - Receive Data Valid/MII Drive Strength. Input/Tri-State Output, Pin 33.

Asserted high to indicate valid data nibbles are present on RXD[3:0].

At power-up or at reset, this pin is used as an input to determine the drive strength of the MII output

drivers. When the pin is low, all MII output drivers will be standard 4 mA CMOS drivers. When high,

additional drive strength will be added to the MII output drivers. This pin includes a weak internal pull-

down (> 20 K

Ω), or the value may be set by an external 4.7 KΩ pull-up or pull-down resistor.

In order to conform with Annex 22B of the IEEE 802.3u specification, this pin should be pulled high

during power-up or reset and should have an external 33

Ω series resistor. For systems not required to

drive external connectors and cables as described in the IEEE802.3u specification, it may be possible to

reduce overall power consumption by pulling the pin low at power-up or reset, and the external series

resistor may not be necessary.

RX_EN - Receive Enable. Input, Pin 14.

When high, signals RXD[3:0], RX_CLK, RX_DV, and RX_ER are enabled. When low, these signals are

tri-stated. RX_EN allows the received data signals of multiple PHY transceivers to share the same MII

bus.

This pin includes a weak internal pull-up (> 150 K

Ω), or the value may be set by an external 10 KΩ pull-

up or pull-down resistor.

CS8952 数据表(PDF) 70 Page - Cirrus Logic