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GS2972 3Gb/s, HD, SD SDI Transmitter

Product Brief

44723 - E

June 2008

Description

The GS2972 is a complete SDI Transmitter, generating a

SMPTE 424M, SMPTE 292M, SMPTE 259M-C or DVB-ASI

compliant Serial Digital Output signal.

The integrated ClockCleaner™ allows the device to accept

parallel clocks with greater than 300ps input jitter and still

provide a SMPTE compliant Serial Digital Output.

The device can operate in four basic user-selectable modes:

SMPTE mode, DVB-ASI mode, Data-Through mode, and

Standby mode.

In SMPTE mode, the GS2972 performs SMPTE scrambling

and NRZ to NRZI coding. In addition, the device can insert

TRS words, calculate and insert line numbers and line based

CRCs, re-map illegal code words, map 8-bit TRS to 10-bit

TRS, calculate and insert EDH CRCs and flags, and insert

SMPTE 352M payload identifier packets. All of the

processing features are optional, and may be disabled via

external control pins and/or via the Host Interface.

The GS2972 provides ancillary data insertion in SMPTE

mode as well. The entire ancillary packet is programmed

into internal registers through the GSPI Host Interface,

including the Ancillary Data Flag (ADF), Data Identification

words (DID and SDID) and checksum. The GS2972 then

recalculates the checksum and inserts the complete

ancillary packet into the video stream.

The user may present the parallel data as either SMPTE

425M Level B or Level A. If the parallel data is presented as

Level A, it may be processed and serialized as Level A or

converted to Level B (conversion only available for 1080p

50/60 4:2:2 10-bit). If the parallel data is presented as Level

B then the serial data will also be Level B.

In DVB-ASI mode, the device will perform 8b/10b encoding

prior to transmission.

In Data-Through mode, all SMPTE and DVB-ASI processing

is disabled, and the device can be used as a simple parallel

to serial converter.

The device can also be placed in a lower power Standby

mode. In this mode, no signal is generated at the output.

Parallel data inputs must be provided in 20-bit or 10-bit

multiplexed format for 3Gb/s, HD and SD video rates. For

1080p 50/60 4:2:2 10-bit video formats, the video data can

be presented at the parallel bus with Y on 10 bits and Cb/Cr

on the other 10 bits. As such, this parallel bus can interface

directly with video processor ICs. For all other format

described in SMPTE 425M, the user must map the data to the

20-bit virtual interface as described in the standard. The

device can accept both the 20-bit virtual interface directly,

or the equivalent pre-multiplexed 10-bit format. The

associated Parallel Clock input signal operates at 148.5 or

148.5/1.001MHz (for all 3Gb/s HD 10-bit multiplexed

modes), 74.25 or 74.25/1.001MHz (for HD 20-bit mode),

27MHz (for SD 10-bit mode) and 13.5MHz (for SD 20-bit

mode).

Note: for 3Gb/s 10-bit mode the device operates in Dual

Data Rate (DDR) mode, where the data is sampled at both

the rising and falling edges of the clock. This reduces the I/O

speed requirements of the downstream devices.

Application: Multi-format Digital VTR/Video Server

Storage:

Tape/HDD/Solid State

Audio

Processor

Video

Processor

20-bit

HV F/P CLK

Audio Inputs

V ideo Inputs

GS4911

Audio Clocks

GS2972

3G-SDI

Sync

Seperator

Analog

Sync

AUDIO 1/ 2

AUDIO 3/ 4

AUDIO 5/ 6

AUDIO 7/ 8

XTAL

Application: 3Gb/s SDI Test Signal Generator

GS4911

Analog

Sync

Sync

Seperator

Video

Signal

Generator

XTAL

Audio

Generator

Memory

HV F/PCLK

Audio Clocks

20-bit

GS2972

3G-SDI

AE S 1/ 2

AE S 3/ 4

AE S 5/ 6

AE S 7/ 8

HV F/PCLK

Keyer

Keyer

Application: Multi-format Presentation Switcher

(Output Stage)

DVE

Mixers

Key & Fill

Logo

Inserter

Image

Store

Key/Fill

Inputs

GS2972

10-bit + Clk

20-bit + Clk

SD/HD/3G-SDI

Auxiliary

Preview

Program

Audio

Mixer

AE S from Input Dem ux

V oice-Over

P reset AE S In

Program AE S In

P rogram AE S Out

P review AE S Out

I2S Audio + Clocks

20-bit + Clk

GS4911

Analog

Sync

XTAL

Sync

Seperator

Clock &

Sync Distribution

GS2972

GS2972

SD/HD/3G-SDI

SD/HD/3G-SDI