adv7390 Analog Devices, Inc., adv7390 Datasheet - Page 52

• Manufacturer Part Number: adv7390
• Description: Low Power, Chip Scale 10-bit Sd/hd Video Encoder
• Manufacturer: Analog Devices, Inc.

ADV7390/ADV7391/ADV7392/ADV7393
SD HUE ADJUST CONTROL
Subaddress 0xA0
When enabled, the SD hue adjust control register
(Subaddress 0xA0) is used to adjust the hue on the SD
composite and chroma outputs. This feature can be
enabled using Subaddress 0x87, Bit 2.
Subaddress 0xA0 contains the bits required to vary the hue of
the video data, that is, the variance in phase of the subcarrier
during active video with respect to the phase of the subcarrier
during the color burst. The ADV739x provides a range of
±22.5° in increments of 0.17578125°. For normal operation
(zero adjustment), this register is set to 0x80. Values 0xFF and
0x00 represent the upper and lower limits, respectively, of the
attainable adjustment in NTSC mode. Values 0xFF and 0x01
represent the upper and lower limits, respectively, of the
attainable adjustment in PAL mode.
The hue adjust value is calculated using the following equation:
where = HCR
For example, to adjust the hue by +4°, write 0x97 to the hue
adjust control register:
where the sum is rounded to the nearest integer.
To adjust the hue by −4°, write 0x69 to the hue adjust control
register:
where the sum is rounded to the nearest integer.
SD BRIGHTNESS DETECT
Subaddress 0xBA
The ADV739x allows monitoring of the brightness level of the
incoming video data. The SD brightness detect register
(Subaddress 0xBA) is a read-only register.
SD BRIGHTNESS CONTROL
Subaddress 0xA1, Bits[6:0]
When this feature is enabled, the SD brightness/WSS control
register (Subaddress 0xA1) is used to control brightness by
adding a programmable setup level onto the scaled Y data. This
feature can be enabled using Subaddress 0x87, Bit 3.
Hue Adjust (°) = 0.17578125° (HCR
⎛
⎜
⎝
⎛
⎜
⎝
. 0
. 0
17578125
17578125
−
4
4
d
hue adjust control register (decimal)
⎞
⎟
⎠
⎞
⎟
⎠
+
+
128
128
≈
≈
151
105
100 IRE
d
d
0 IRE
=
=
x 0
x 0
97
9 6
NTSC WITHOUT PEDESTAL
VALUE ADDED
d
− 128)
NO SETUP
Figure 70. Examples of Brightness Control Values
Rev. 0 | Page 52 of 96
POSITIVE SETUP
VALUE ADDED
For NTSC with pedestal, the setup can vary from 0 IRE to 22.5 IRE.
For NTSC without pedestal (see Figure 70) and for PAL, the
setup can vary from −7.5 IRE to +15 IRE.
The SD brightness control register is an 8-bit register. The seven
LSBs of this 8-bit register are used to control the brightness
level, which can be a positive or negative value.
For example,
To add +20 IRE brightness level to an NTSC signal with
pedestal, write 0x28 to Subaddress 0xA1.
To add –7 IRE brightness level to a PAL signal, write 0x72 to
Subaddress 0xA1.
Table 44. Sample Brightness Control Values
Setup Level
(NTSC) with
Pedestal
22.5 IRE
15 IRE
7.5 IRE
0 IRE
1
SD INPUT STANDARD AUTO DETECTION
Subaddress 0x87, Bit 5
The ADV739x include an SD input standard auto detect feature
that can be enabled by setting Subaddress 0x87, Bit 5 to Bit 1.
When enabled, the ADV739x can automatically identify an
NTSC or PAL B/D/G/H/I input stream. The ADV739x
automatically updates the subcarrier frequency registers with
the appropriate value for the identified standard. The ADV739x
is also configured to correctly encode the identified standard.
The SD standard bits (Subaddress 0x80, Bits[1:0]) and the
subcarrier frequency registers are not updated to reflect the
identified standard. All registers retain their default or user-
defined values.
Values in the range of 0x3F to 0x44 can result in an invalid output signal.
0 × (SD Brightness Value) =
0 × (IRE Value × 2.015631) =
0 × (20 × 2.015631) = 0 × (40.31262) ≈ 0x28
0 × (SD Brightness Value) =
0 × (IRE Value × 2.075631) =
0 × (7 × 2.015631) = 0x(14.109417) ≈ 0001110b
0001110b into two’s complement = 1110010b = 0x72
NEGATIVE SETUP
VALUE ADDED
Setup Level
(NTSC) Without
Pedestal
15 IRE
7.5 IRE
0 IRE
−7.5 IRE
+7.5 IRE
–7.5 IRE
Setup
Level
(PAL)
15 IRE
7.5 IRE
0 IRE
−7.5 IRE
1
Brightness
Control Value
0x1E
0x0F
0x00
0x71