Features

Lowest Cost Solution for high quality

multimedia networking

• Data rate of over 24.5 Mbit/s

⇒ Bandwidth allocable for both asynchronous and

synchronous data

⇒ Independent 768 kbit/s control channel

• Designed for ultra-low cost network nodes

⇒ On-chip support of fiber optic physical layer

⇒ Stand-alone operation (no MCU) by remote

access

⇒ No buffering required for audio applications

On-chip Network Management Functions

• Automatic multimedia channel allocation

• Automatic wake-up on sensing network activity

• Node position and delay detection

• Fail-safe node bypass and error reporting

Flexible I/O

• Consumer Electronic / Multimedia I/O

⇒ Multiple speed CD & Media player interfaces

⇒ Real-time I/O with various data formats

⇒ 1-8x speed IEC 958 (S/PDIF or AES-EBU) port

⇒ Transparent channel with sample rate up to

3 MHz

• Control I/O

⇒ High speed IIC/SPI serial control interface

⇒ FIFO buffered 8-bit parallel control interface

⇒ Transparent interface up to 128 kbit/s.

Easy System Integration

• Low power and zero power mode

• Low power 5 V operation

• 44-pin TQFP package

Description

The OS8104 is a highly integrated CMOS Transceiver

IC with full support for the 24.5 Mbit/s MOST Multimedia and Control network.

This high performance, low cost, real-time network

utilizes a ring topology and a plastic optical fiber (POF)

physical layer, both of which are supported directly by

the OS8104.

All relevant network management functions are

handled on-chip. An ultra-low jitter PLL guarantees

high quality audio and video transmission, and clock

recovery over a wide frequency range.

The 24.5 Mbit/s aggregate bit rate provides the

capability to network up to 60 byte-wide synchronous

data channels (equivalent to 15 stereo, CD-audio

channels) or any appropriate combination of synchronous and asynchronous data streams. Control data

is also networked, transparently to the source data

channels, at an aggregate bit rate of 768 kbits/s.

The OS8104 can be managed remotely, from any

other network node; or locally via the Control Port in

I

2

C or SPI more, or through a parallel format.

Programmable serial and parallel real-time data

interfaces, with different clock and data modes,

support connections to multiple speed CD drives and

other consumer electronic devices, as well as comple–

mentary ICs such as A/D and D/A converters or DSPs.

2 General Overview

2.1 Functional Description

The OS8104 chip contains a RISC microcontroller-based MOST Routing Engine and several peripherals

including a clock manager, Source Data Ports, wake-up logic and an I2

C/SPI/parallel Control Port.

SDA

SCL

[AD0,SDIN]

[AD1, /CS]

MOST

Routing

Engine

Source

Data

Ports

Clock

Manager

I2C/SPI

Port

SX0..3,D4..7

SR0..3,D0..3

XTI

XTO

TX

RX

Network

Interface

Wake-up

Logic

&

Power

Management

Figure 2-1: MOST Routing Engine

The network interface includes an ultra-low jitter Phase Lock Loop (PLL) and a channel demodulator on

the input side (RX). The network output (TX) provides a channel-coded signal. Those signals can be

connected directly to optical receiving/transmitting devices (FOT units) or balanced line drivers. The line

quality can be monitored using the built-in error detection circuit.

Each device can generate the network clock or synchronize to it; however, only one device can generate

the clock and the frame structure for a particular network. Various A/D converters, D/A converters, digital

signal processors, and Media Players (CD-AUDIO/VIDEO/ROM etc.) can be synchronized through one of

the many clock and serial interface modes.

The Source Data Ports provide a synchronous data interface to the network, generally used for

multimedia devices. Data sources and sinks can be connected to the Source Ports to transfer data to

another node on the network, or receive data from another node on the network. The Source Ports

support up to four simultaneous inputs and four simultaneous outputs for transferring real-time data

between external peripherals and the MOST network.