Datasheet

Table Of Contents
ADV7188
Rev. A | Page 87 of 112
Bit
1
Address Register Bit Description 7 6 5 43210Comments Notes
FREE_RUN_ACT. x 1 = free-run mode active Blue screen output
STD_FLD_LEN. x 1 = field length standard Correct field length found
INTERLACED. x 1 = interlaced video detected Field sequence found
PAL_SW_LOCK. x 1 = swinging burst detected Reliable swinging burst sequence
Reserved. 0 0
0 Crystal used to derive
28.63636 MHz clock
XTAL_TTL_SEL.
1 External TTL level clock supplied
Analog Control
Internal (Write Only)
Reserved. 0 0 0 0 0
Reserved. 0 0 1 0 Set to default
0 Current sources switched off CCLEN. Current clamp enable. This bit allows
the user to switch off the current sources in
the analog front end.
1 Current sources enabled
0x14 Analog Clamp
Control
Reserved.
0 0 0 Set to default
Reserved. x x x x Set to default
0 Disable digital clamp freeze DCFE. Digital clamp freeze enable.
1 Enable digital clamp freeze
0 0 Slow (TC = 1 sec)
01 Medium (TC = 0.5 sec)
10 Fast (TC = 0.1 sec)
DCT [1:0]. Digital clamp timing. These bits
determine the time constant of the digital
fine-clamp circuitry.
11 TC dependent on video
0x15 Digital Clamp
Control 1
Reserved.
0 Set to default
00000Automatically uses wide notch
filter for poor quality sources and
wideband filter with comb for
good quality input
0 0 0 0 1 Automatically uses narrow notch
filter for poor quality sources and
wideband filter with comb for
good quality input
Decoder selects optimum Y-shaping
filter depending on CVBS quality.
00010SVHS 1
00011SVHS 2
00100SVHS 3
00101SVHS 4
00110SVHS 5
00111SVHS 6
01000SVHS 7
01001SVHS 8
01010SVHS 9
01011SVHS 10
01100SVHS 11
01101SVHS 12
01110SVHS 13
01111SVHS 14
10000SVHS 15
10001SVHS 16
10010SVHS 17
0x17 Shaping Filter
Control
10011SVHS 18 (CCIR 601)
10100PAL NN 1
10101PAL NN 2
10110PAL NN 3
10111PAL WN 1
11000PAL WN 2
11001NTSC NN1
11010NTSC NN2
11011NTSC NN3
11100NTSC WN 1
11101NTSC WN 2
11110NTSC WN 3
YSFM [4:0]. Selects Y-shaping filter mode
when in CVBS only mode. These bits allow
the user to select a wide range of low-pass
and notch filters.
11111Reserved
If one of these modes is selected, the
decoder does not change filter modes.
A fixed filter response (the one selected)
is used regardless of video quality.