CS8952(2001) Просмотр технического описания (PDF) - Cirrus Logic

Номер в каталоге

Компоненты Описание

производитель

CS8952
(Rev.:2001)

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

Cirrus Logic 

CS8952

2. INTRODUCTION

The CS8952 is a complete physical-layer transceiv-

er for 100BASE-TX and 10BASE-T applications.

Additionally, the CS8952 can be used with an ex-

ternal optical module for 100BASE-FX.

2.1 High Performance Analog

The highly integrated mixed-signal design of the

CS8952 eliminates the need for external analog cir-

cuitry such as external transmit or receive filters.

The CS8952 builds upon Cirrus Logic’s experience

in pioneering the high-volume manufacturing of

10BASE-T integrated circuits with “true” internal

filters. The CS8952, CS8920, CS8904, and

CS8900 include fifth-order, continuous-time But-

terworth 10BASE-T transmit and receive filters, al-

lowing those products to meet 10BASE-T wave

shape, emission, and frequency content require-

ments without external filters.

2.2 Low Power Consumption

The CS8952 is implemented in low power CMOS,

consuming only 135 mA typically. Three low-pow-

er modes are provided to make the CS8952 ideal

for power sensitive applications such as CardBus.

2.3 Application Flexibility

The CS8952’s digital interface and operating

modes can be tailored to efficiently support a wide

variety of applications. For example, the Media In-

dependent Interface (MII) supports 100BASE-TX,

100BASE-FX and 10BASE-T NIC cards, switch

ports and router ports. Additionally, the low-laten-

cy “repeater” interface mode minimizes data delay

through the CS8952, facilitating system compli-

ance with overall network delay budgets. To sup-

port 10BASE-T applications, the CS8952 provides

a 10BASE-T serial port (Seven-wire ENDEC inter-

face).

2.4 Typical Connection Diagram

Figure 1 illustrates a typical MII to CS8952 appli-

cation with twisted-pair and fiber interfaces. Refer

to the Analog Design Considerations section for

detailed information on power supply requirements

and decoupling, crystal and magnetics require-

ments, and twisted-pair and fiber transceiver con-

nections.

3. FUNCTIONAL DESCRIPTION

The CS8952 is a complete physical-layer transceiv-

er for 100BASE-TX and 10BASE-T applications.

It provides a Physical Coding Sub-layer for com-

munication with an external MAC (Media Access

Controller). The CS8952 also includes a complete

Physical Medium Attachment layer and a

100BASE-TX and 10BASE-T Physical Medium

Dependent layer. Additionally, the CS8952 pro-

vides a PECL interface to an external optical mod-

ule for 100BASE-FX applications.

The primary digital interface to the CS8952 is an

enhanced IEEE 802.3 Media Independent Interface

(MII). The MII supports parallel data transfer, ac-

cess to the CS8952 Control and Status registers,

and several status and control pins. The CS8952's

operating modes can be tailored to support a wide

variety of applications, including low-latency

100BASE-TX repeaters, switches and MII-based

network interface cards.

For 100BASE-TX applications, the digital data in-

terface can be either 4-bit parallel (nibbles) or 5-bit

parallel (code-groups). For 10BASE-T applica-

tions, the digital data format can be either 4-bit par-

allel (nibbles) or one-bit serial.

The CS8952 is controlled primarily by configura-

tion registers via the MII Management Interface.

Additionally, a number of the most fundamental

register bits can be set at power-up and reset time

by connecting pull-up or pull-down resistors to ex-

ternal pins.

The CS8952's MII interface is enhanced beyond

IEEE requirements by register extensions and the

addition of pins for MII_IRQ, RX_EN, and ISO-

DEF signals. The MII_IRQ pin provides an inter-

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

19

Share Link: