GS1672 datasheet(30/116 Pages) SEMTECH

30 / 116 page

GS1672 HD/SD-SDI Serializer with Complete SMPTE

Audio & Video Support

Data Sheet

53623 - 6

July 2011

30 of 116

The GS1672 does not differentiate between a signal carrying video and a signal carrying

SDTI or HD-SDTI data in SD or HD formats. The user is responsible for ensuring that the

headers and data are not corrupted.

4.2.2 Parallel Input in DVB-ASI Mode

The GS1672 is in DVB-ASI mode when the SMPTE_BYPASS pin is set LOW, the DVB_ASI

pin is set HIGH, and the RATE_SEL0 pin is set HIGH. In this mode, all SMPTE processing

features are disabled.

When operating in DVB-ASI mode, the device must be set to 10-bit mode by setting the

20BIT/10BIT pin LOW. The device will accept 8-bit data words on DIN[17:10], where

DIN17 = HIN is the most significant bit of the encoded transport stream data and DIN10

= AIN is the least significant bit. In addition, DIN19 and DIN18 will be configured as the

DVB-ASI control signals INSSYNCIN and KIN respectively.

DIN19 = INSSYNCIN

DIN18 = KIN

DIN17~10 = HIN ~ AIN where AIN is the least significant bit of the transport stream data.

4.2.3 Parallel Input in Data-Through Mode

Data-Through mode is enabled when the SMPTE_BYPASS pin and the DVB_ASI pin are

LOW.

In this mode, data at the input bus is serialized without any encoding, scrambling or

word alignment taking place.

The input data width is controlled by the setting of the 20BIT/10BIT pin as shown in

Table 4-2 above.

NOTE:

When in HD 10-bit mode, asserting the SMPTE_BYPASS LOW to put the device

in SMPTE-BYPASS mode will create video errors. If the user desires to use the device as

a simple serializer in HD 10-bit mode, all video processing features may be disabled by

setting the IOPROC_EN/DIS pin LOW.

4.2.4 Parallel Input Clock (PCLK)

The frequency of the PCLK input signal of the GS1672 is determined by the input data

format and operating mode selection.

Table 4-3 below lists the input PCLK rates and input signal formats according to the

external selection pins for the GS1672.

GS1672 Datasheet(PDF) 30 Page - Semtech Corporation