ADV7181B
Rev. B | Page 34 of 100
NSFSEL[1:0] Split Filter Selection NTSC,
Address 0x19[3:2]
The NSFSEL[1:0] control selects how much of the overall signal
bandwidth is fed to the combs. A narrow split filter selection
gives better performance on diagonal lines, but leaves more dot
crawl in the final output image. The opposite is true for selecting
a wide bandwidth split filter.
Table 43. NSFSEL Function
NSFSEL[1:0] Description
00 (default)
Narrow
01 Medium
10
Medium
11 Wide
CTAPSN[1:0] Chroma Comb Taps NTSC,
Address 0x38[7:6]
Table 44. CTAPSN Function
CTAPSN[1:0] Description
00
Do not use
01
NTSC chroma comb adapts 3 lines (3 taps) to 2
lines (2 taps)
10 (default)
NTSC chroma comb adapts 5 lines (5 taps) to 3
lines (3 taps)
11
NTSC chroma comb adapts 5 lines (5 taps) to 4
lines (4 taps)
CCMN[2:0] Chroma Comb Mode NTSC, Address 0x38[5:3]
Table 45. CCMN Function
CCMN[2:0]
Description
Configuration
Adaptive 3-line chroma comb for CTAPSN = 01
Adaptive 4-line chroma comb for CTAPSN = 10
0xx (default)
Adaptive comb mode
Adaptive 5-line chroma comb for CTAPSN = 11
100 Disable
chroma
comb
Fixed 2-line chroma comb for CTAPSN = 01
Fixed 3-line chroma comb for CTAPSN = 10
101
Fixed chroma comb (top lines of line memory)
Fixed 4-line chroma comb for CTAPSN = 11
Fixed 3-line chroma comb for CTAPSN = 01
Fixed 4-line chroma comb for CTAPSN = 10
110
Fixed chroma comb (all lines of line memory)
Fixed 5-line chroma comb for CTAPSN = 11
Fixed 2-line chroma comb for CTAPSN = 01
Fixed 3-line chroma comb for CTAPSN = 10
111
Fixed chroma comb (bottom lines of line memory)
Fixed 4-line chroma comb for CTAPSN = 11
YCMN[2:0] Luma Comb Mode NTSC, Address 0x38[2:0]
Table 46. YCMN Function
YCMN[2:0] Description
Configuration
0xx (default)
Adaptive comb mode
Adaptive 3-line (3 taps) luma comb
100
Disable luma comb
Use low-pass/notch filter; see the Y-Shaping Filter section
101
Fixed luma comb (top lines of line memory)
Fixed 2-line (2 taps) luma comb
110
Fixed luma comb (all lines of line memory)
Fixed 3-line (3 taps) luma comb
111
Fixed luma comb (bottom lines of line memory)
Fixed 2-line (2 taps) luma comb
PAL Comb Filter Settings
Used for PAL-B/G/H/I/D, PAL-M, PAL-combinational N,
PAL-60, and NTSC443 CVBS inputs.
PSFSEL[1:0] Split Filter Selection PAL, Address 0x19[1:0]
The PSFSEL[1:0] control selects how much of the overall signal
bandwidth is fed to the combs. A wide split filter selection
eliminates dot crawl, but shows imperfections on diagonal lines.
The opposite is true for selecting a narrow bandwidth split filter.
Table 47. PSFSEL Function
PSFSEL[1:0] Description
00
Narrow
01 (default)
Medium
10
Wide
11 Widest
