GS2985 Datasheet, PDF (4/45 Pages) Gennum Corporation – Uses standard 27MHz crystal

Contents
Features.................................................................................................................................................................1
Applications.........................................................................................................................................................1
Description ...........................................................................................................................................................1
Revision History .................................................................................................................................................2
1. Pin Out...............................................................................................................................................................5
1.1 Pin Assignment ..................................................................................................................................5
1.2 Pin Descriptions ................................................................................................................................6
2. Electrical Characteristics ............................................................................................................................9
2.1 Absolute Maximum Ratings ..........................................................................................................9
2.2 DC Electrical Characteristics ........................................................................................................9
2.3 AC Electrical Characteristics ..................................................................................................... 10
3. Input/Output Circuits ............................................................................................................................... 13
4. Detailed Description.................................................................................................................................. 18
4.1 Serial Data Input ............................................................................................................................ 18
4.2 Modes of Operation ...................................................................................................................... 18
4.3 Input Trace Equalization ............................................................................................................. 18
4.4 4:1 Input Mux .................................................................................................................................. 19
4.5 Crystal Buffer .................................................................................................................................. 20
4.6 LOS (Loss Of Signal) Detection .................................................................................................. 20
4.7 Serial Digital Reclocker ............................................................................................................... 21
4.8 Lock Detection ................................................................................................................................ 21
4.8.1 Lock Detect and Asynchronous Lock ......................................................................... 22
4.9 Serial Data Output ......................................................................................................................... 22
4.9.1 Output Signal Interface Levels...................................................................................... 22
4.9.2 Adjustable Output Swing................................................................................................ 22
4.9.3 Output De-emphasis ........................................................................................................ 22
4.10 Automatic and Manual Data Rate Selection ...................................................................... 23
4.11 SD/HD Indication ........................................................................................................................ 24
4.12 Bypass Mode ................................................................................................................................. 25
4.13 DVB-ASI ......................................................................................................................................... 25
4.14 Output Mute and Data/Clock Output Selection ............................................................... 25
4.15 Host Interface ............................................................................................................................... 26
4.15.1 Introduction ...................................................................................................................... 26
4.15.2 Legacy Mode & Start-up................................................................................................ 26
4.15.3 Host Interface Mode & Start-up.................................................................................. 26
4.15.4 Clock & Data Timing....................................................................................................... 27
4.15.5 Single Device Operation ............................................................................................... 27
4.15.6 Write Operation - Single Device ................................................................................ 28
4.15.7 Read Operation - Single Device ................................................................................. 28
4.15.8 Daisy Chain Operation.................................................................................................. 31
4.15.9 Read & Write Operation - Daisy Chained Devices............................................... 32
4.15.10 Writing to all Devices .................................................................................................. 32
GS2985 Multi-Rate SDI Reclocker with Equalization &
De-emphasis
Data Sheet
36663 - 5
July 2012
4 of 45
Proprietary & Confidential