ch7028b Chrontel, ch7028b Datasheet - Page 14

• Manufacturer Part Number: ch7028b
• Description: Chrontel Ch7028b Sdtv Encoder
• Manufacturer: Chrontel

CHRONTEL
When the input is a YCrCb data stream the color-difference data will be transmitted at half the data rate of the
luminance data, with the sequence being set as Cb, Y, Cr, Y, where Cb0,Y0,Cr0 refers to co-sited luminance and color-
difference samples and the following Y1 byte refers to the next luminance sample, per ITU-R BT.656 standards (the
clock frequency is dependent upon the current mode, and is not 27MHz as specified in ITU-R BT.656). In YCbCr 4:2:2
with embedded sync mode, the hardware can detect the connection error and correct it automatically. All non-active
pixels should be 0 in RGB formats, and 16 for Y, 128 for Cr and Cb in YCrCb formats.
2.2
2.2.1 TV Output
The CH7028B support the following output formats:
Table 4: Supported SDTV Standards
CVBS, S-video output are supported.
2.2.2 Video DAC Output
The DAC output is configured by the register bits VFMT[2:0]. DACS[1:0] bits are used to control the multiple output
format i.e. dual CVBS or S-Video output. DACSP[2:0] bits are to swap the DAC output sequence such as CVBS, S-
Video or S-Video, CVBS. Detailed information of these bits are described in register bits description section of this
document. Table 4 below lists the DAC output configurations of the CH7028B:
2.2.3 DAC Single/Double Termination
The DAC output of CH7028B can be single terminated or double terminated. Using single termination will save power
consumption while double termination is likely to minimize the reflection from the cable. Refer to the description of
register bit SEL_R.
2.2.4 TV Connection Detect
CH7028B can detect the TV connection by setting register SPPSNS. It can detect which DAC is connected, short to
ground or not connected.
2.2.5 Picture Enhancement
14
No.
0
1
2
3
4
5
6
7
Chip Output
Standards
NTSC-M
NTSC-J
NTSC-443
PAL-B/D/G/H/I
PAL-M
PAL_N
PAL-Nc
PAL_60
Table 5: Video DAC Configurations for CH7028B
DAC0
CVBS
CVBS
C
Field Rate (Hz)
60/1.001
60/1.001
60/1.001
50
60/1.001
50
50
60/1.001
DAC1
CVBS
Y
209-1000-001
Total
858x525
858x525
858x525
864x625
858x525
864x625
864x625
858x525
Rev. 1.1,
CH7028B
Scan Type
Interlaced
Interlaced
Interlaced
Interlaced
Interlaced
Interlaced
Interlaced
Interlaced
08/21/2008