ADV7191 Analog Devices, ADV7191 Datasheet - Page 39

• Manufacturer Part Number: ADV7191
• Description: Video Encoder with Six 10-Bit DACs and Video Encoder with Six DAC Outputs
• Manufacturer: Analog Devices

EXAMPLE
2. Standard: PAL. To add –7 IRE brightness level write 72
HUE ADJUST CONTROL REGISTER (HCR)
(Address (SR5–SR0) = 20H)
the hue on the composite and chroma outputs. Figure 74 shows
the operation under control of this register.
HCR Bit Description
Hue Adjust Value (HCR0–HCR7)
These eight bits represent the value required to vary the hue of
the video data, i.e., the variance in phase of the subcarrier during
active video with respect to the phase of the subcarrier during the
colorburst. The ADV7190/ADV7191 provides a range of ± 22.5°
increments of 0.17578125°. For normal operation (zero adjust-
ment) this register is set to 80Hex. FFHex and 00Hex represent
the upper and lower limit (respectively) of adjustment attainable.
Hue Adjust [°] = 0.17578125° × (HCR
Adjust Value
Example:
To adjust the hue by 4° write 97
Register:
To adjust the hue by (–4°) write 69
Register:
1. Standard: NTSC with Pedestal. To add +20 IRE brightness level, write 28
he hue control register is an 8-bit-wide register used to adjust
ounded to the nearest integer.
HCR7
HCR6
(–4/0.17578125) + 128 = 10d
(4/0.17578125) + 128 = 151
[Brightness Control Register Value]
HCR5
100 IRE
0 IRE
HUE ADJUST VALUE
HCR4
HCR7 – HCR0
NTSC WITHOUT PEDESTAL
[|IRE Value| × 2.015631] = [7 × 2.015631] = [14.109417] = 0001110
NO SETUP VALUE
ADDED
ZERO MUST BE
WRITTEN TO
h
HCR3
THIS BIT
to the Hue Adjust Control
h
BCR7
BCR7
to the Hue Adjust Control
d
– 128); for positive Hue
[0001110] into two’s complement = 1110010
HCR2
d
d
BCR6
= 97
h
69
= [IRE Value
HCR1
h
h
BCR5
POSITIVE SETUP
VALUE ADDED
WRITE TO BRIGHTNESS
CONTROL REGISTER: 12
HCR0
h
BCR4
into the Brightness Control Register:
BRIGHTNESS VALUE
BCR6 – BCR0
2.015631]
BCR3
BRIGHTNESS CONTROL REGISTERS (BCR)
(Address (SR5–SR0) = 21H)
The brightness register is an 8-bit-wide register which allows
brightness control. Figure 75 shows the operation under control
of this register.
BCR BIT DESCRIPTION
Brightness Value (BCR0–BCR6)
Seven bits of this 8-bit-wide register are used to control the
brightness level. The brightness is controlled by adding a pro-
grammable setup level onto the scaled Y data. This brightness
level can be a positive or negative value.
The programmable brightness level in NTSC without pedestal
and PAL are max 15 IRE and min –7.5 IRE, in NTSC with
pedestal max 22.5 IRE and min 0 IRE.
S
Level in
NTSC with
Pedestal
22.5 IRE
15 IRE
7.5 IRE
0 IRE
NOTE
Values in the range from 3F
etup
h
h
BCR2
= [20 × 2.015631]
h
Table IV. Brightness Control Register Value
NEGATIVE SETUP
VALUE ADDED
WRITE TO BRIGHTNESS
CONTROL REGISTER: 6E
into the Brightness Control Register:
BCR1
b
= 72
Setup
Level in
NTSC No
Pedestal
15 IRE
7.5 IRE
0 IRE
–7.5 IRE
h
BCR0
h
to 44
h
h
= [40.31262]
h
might result in an invalid output signal.
ADV7190/ADV7191
b
+7.5 IRE
–7.5 IRE
Setup
Level in
PAL
15 IRE
7.5 IRE
0 IRE
–7.5 IRE
h
= 28
h
Brightness
Control
Register
Value
1E
0F
00
71
h
h
h
h