AMD SC1201, SC1200 Tvout Block, Flicker Filter and Scan Rate Conversion, Vesa, Video Output Port

Video Processor Module 32579B

7.2.4TVOUT Block

The TVOUT block provides a full-featured TV output signal. NTSC TV and PAL TV formats are both supported. A YUV progressive scan image is delivered to the TVOUT block from the Mixer/Blender block. Integrated horizontal scaling, flicker filtering, scan rate conversion, and TV encoder pro- duce a high quality TV output. See TVOUT block diagram, Figure 7-13.

7.2.4.1Flicker Filter and Scan Rate Conversion

The flicker filter uses a 3-line moving window buffer, and has fixed coefficients. The maximum line width is 768 pix- els. F4BAR0+Memory Offset 814h[30:29] enables the flicker filter’s two operating modes: Flicker filter interlaced video data and flicker filter progressive video data.

Flicker Filter, Interlaced Video and

YUV Mixing/Blending Mode

This is the recommended mode. With this mode only the graphics data is flicker filtered. Interlaced video and YUV blending must be the Mixer/Blender block’s mode (see Sec- tion 7.2.3 "Mixer/Blender Block" on page 323). In this mode, the Mixer/Blender block supports the flicker filter process (see Figure 7-10 on page 323). Then the mixed/ blended data is flicker filtered using the formula shown in Table 7-4.Using the ½, 1, ½ coefficients the graphics data is pre-divided by 2 in the Mixer/Blender block. The video data is interlaced so the previous and next line of the video data stream is null. Therefore when the coefficients are applied to the mixed data, the graphics data is modified and the video data is not.

YUV Image from

Mixer/Blender

3-Line Moving Window

Buffer

Flicker Filter

Progressive Scan to

Interlace Scan

Converter

VESA	Video Output Port
Encoder

Pre-Encoder

Horizontal

Scaler

TV Encoder

Timing Generator

TV

Encoder

TV DACs

Figure 7-13. TVOUT Block Diagram

Table 7-4. Flicker Filter Operation

Mixer/Blender Block		Flicker Filter ½, 1, ½ Coefficients
½ Y Flicker Filter - Graphics Pixel	Graphics Pixel		Video Pixel
Graphics Y(n-1) * ½ = ½ GY(n-1)	½ GY * ½ =	¼ GY(n-1)	Video Y (m-1)
Graphics Y(n) * ½ = ½ GY(n)	½ GY * 1 =	½ GY(n)	Null * ½ =	0
Graphics Y(n+1) * ½ = ½ GY(n+1)	½ GY * ½ =	¼ GY(n+1)	Video Y (m) * 1=	VY(m)
			Null * ½ =	0
			Video Y (m+1)
	----------------			--------------
	1 GY pixel			1 VY pixel

AMD Geode™ SC1200/SC1201 Processor Data Book 329