Data Sheet
ADV7180
BETACAM, Enable Betacam Levels, Address 0x01[5]
PW_UPD, Peak White Update, Address 0x2B[0]
If YPrPb data is routed through the ADV7180, the automatic
gain control modes can target different video input levels, as
outlined in Table 44. The BETACAM bit is valid only if the
input mode is YPrPb (component). The BETACAM bit sets the
target value for AGC operation.
The peak white and average video algorithms determine the
gain based on measurements taken from the active video. The
PW_UPD bit determines the rate of gain change. LAGC[2:0] must
be set to the appropriate mode to enable the peak white or average
video mode in the first place. For more information, see the
LAGC[2:0], Luma Automatic Gain Control, Address 0x2C[6:4]
section.
A review of the following sections is useful:
•
•
The MAN_MUX_EN, Manual Input Muxing Enable,
Address 0xC4[7] section for how component video
(YPrPb) can be routed through the ADV7180.
The Video Standard Selection section to select the various
standards, for example, with and without pedestal.
Setting PW_UPD to 0 updates the gain once per video line.
Setting PW_UPD to 1 (default) updates the gain once per field.
Chroma Gain
CAGC[1:0], Chroma Automatic Gain Control,
Address 0x2C[1:0]
The AGC algorithms adjust the levels based on the setting of
the BETACAM bit (see Table 42).
The two bits of color automatic gain control mode select the
basic mode of operation for automatic gain control in the
chroma path.
Table 42. BETACAM Function
BETACAM
Description
0 (default)
Assuming YPrPb is selected as input format:
Selecting PAL with pedestal selects MII.
Selecting PAL without pedestal selects SMPTE.
Selecting NTSC with pedestal selects MII.
Selecting NTSC without pedestal selects SMPTE.
Assuming YPrPb is selected as input format:
Selecting PAL with pedestal selects BETACAM.
Selecting PAL without pedestal selects BETACAM variant.
Selecting NTSC with pedestal selects BETACAM.
1
Selecting NTSC without pedestal selects BETACAM variant.
Table 43. CAGC Function
CAGC[1:0]
Description
00
01
Manual fixed gain (use CMG[11:0])
Luma gain used for chroma
Automatic gain (based on color burst)
Freeze chroma gain
10 (default)
11
Table 44. BETACAM Levels
Name
BETACAM (mV)
0 to +714 (including 7.5% pedestal)
−467 to +467
BETACAM Variant (mV)
0 to +714
−505 to +505
+286
SMPTE (mV)
0 to +700
−350 to +350
+300
MII (mV)
Y
0 to +700 (including 7.5% pedestal)
−324 to +324
+300
Pb and Pr
Sync Depth
+286
Rev. G | Page 37 of 120
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