adv7180 Analog Devices, Inc., adv7180 Datasheet - Page 34

• Manufacturer Part Number: adv7180
• Description: 10-bit, 4 X Oversampling Sdtv Video Decoder
• Manufacturer: Analog Devices, Inc.

ADV7180
BETACAM, Enable Betacam Levels, Address 0x01 [5]
If YPrPb data is routed through the ADV7180, the automatic
gain control modes can target different video input levels, as
outlined in Table 40. Note that the BETACAM bit is valid only if
the input mode is YPrPb (component). The BETACAM bit sets
the target value for AGC operation.
A review of the following sections is useful:
•
•
The automatic gain control (AGC) algorithms adjust the levels
based on the setting of the BETACAM bit (see Table 38).
Table 38. BETACAM Function
BETACAM
0 (default)
1
Table 39. CAGC Function
CAGC[1:0]
00
01
10 (default)
11
Table 40. Betacam Levels
Name
Y
Pb and Pr
Sync Depth
MAN_MUX_EN, Manual Input Muxing Enable,
Address 0xC4 [7] for how component video (YPrPb)
can be routed through the ADV7180.
Video Standard Selection to select the various standards,
for example, with and without pedestal.
Description
Assuming YPrPb is selected as input format
Assuming YPrPb is selected as input format
Description
Manual fixed gain (use CMG[11:0])
Use luma gain for chroma
Automatic gain (based on color burst)
Freeze chroma gain
Betacam (mV)
0 to 714 (incl. 7.5% pedestal)
–467 to +467
286
Selecting PAL with pedestal selects MII
Selecting PAL without pedestal selects SMPTE
Selecting NTSC with pedestal selects MII
Selecting NTSC without pedestal selects SMPTE
Selecting PAL with pedestal selects BETACAM
Selecting PAL without pedestal selects BETACAM variant
Selecting NTSC with pedestal selects BETACAM
Selecting NTSC without pedestal selects BETACAM variant
Betacam Variant (mV)
0 to 714
–505 to +505
286
Rev. B | Page 34 of 112
PW_UPD, Peak White Update, Address 0x2B [0]
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,
refer to the LAGC[2:0], Luma Automatic Gain Control,
Address 0x2C [6:4] section.
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 two bits of color automatic gain control mode select the
basic mode of operation for automatic gain control in the
chroma path.
SMPTE (mV)
0 to 700
–350 to +350
300
MII (mV)
0 to 700 (incl. 7.5% pedestal)
–324 to +324
300