SDA9189X Datasheet, PDF (20/55 Pages) Siemens Semiconductor Group – Quarter PIP Processor

SDA 9189X
2.2.3 Decimation Filters
The input signal is decimated by subsampling with horizontal and vertical filtering. A
special antialias filter improves the frequency response of the luminance channel.
The following decimation filters are implemented:
Horizontal Decimation
2:1
3:1
4:1
6:1
Luminance Filter
{11}
{111}
{1111}
{111111}
Chrominance Filter
{11}
{121}
{1111}
{112211}
Vertical Decimation
2:1
3:1
4:1
6:1
Luminance Filter
{11}
{111}
{1111}
{111111}
Chrominance Filter
{11}
{121}
{1111}
{112211}
The realized chrominance filtering allows omitting the color decoder delay line for PAL
and SECAM demodulation if the color decoder supplies the same output voltages
independent of the kind of operation. In case of SECAM signals an amplification of the
chrominance signals by a factor of 2 is necessary because there is a signal only in every
second line. This chrominance amplification is programmable via I²C Bus (AMSEC).
Semiconductor Group
20
03.96