ADV7191 Analog Devices, ADV7191 Datasheet - Page 31

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

MODE REGISTER 3
MR3 (MR37–MR30)
(Address (SR4–SR0) = 03H)
Mode Register 3 is a 8-bit wide register. Figure 53 shows the
various operations under the control of Mode Register 3.
MR3 BIT DESCRIPTION
Revision Code (MR30–MR31)
This bit is read only and indicates the revision of the device.
VBI_Open (MR32)
This bit determines whether or not data in the Vertical Blanking
Interval (VBI) is output to the analog outputs or blanked. Note
that this condition is also valid in Timing Slave Mode 0. For
further information see Vertical Blanking Data Insertion and
BLANK Input section.
Teletext Enable (MR33)
This bit must be set to 1 to enable teletext data insertion on
the TTX pin.
Teletext Bit Request Mode Control (MR34)
This bit enables switching of the teletext request signal from a
continuous high signal (MR34 = 0) to a bitwise request signal
(MR34 = 1).
Closed Captioning Field Control (MR35–MR36)
These bits control the fields that closed captioning data is dis-
played on, closed captioning information can be displayed on
an odd field, even field or both fields.
Reserved (MR37)
A Logic 0 must be written to this bit.
MODE REGISTER 4
MR4 (MR47–MR40)
(Address (SR4–SR0) = 04H)
Mode Register 4 is a 8-bit wide register. Figure 54 shows the
various operations under the control of Mode Register 4.
MR4 BIT DESCRIPTION
VSYNC_3H Control (MR40)
When this bit is enabled (1) in Slave Mode, it is possible to
drive the VSYNC input low for 2.5 lines in PAL mode and
three lines in NTSC mode. When this bit is enabled in Master
Mode the ADV7190/ADV7191 outputs an active low VSYNC
signal for three lines in NTSC mode and 2.5 lines in PAL mode.
ZERO MUST BE
WRITTEN TO
THIS BIT
MR37
MR37
MR36 MR35
0
0
1
1
CLOSED CAPTIONING
MR36
0
1
0
1
FIELD CONTROL
NO DATA OUT
ODD FIELD ONLY
EVEN FIELD ONLY
DATA OUT
(BOTH FIELDS)
MR35
MR34
TTX BIT REQUEST
MODE CONTROL
0
1
DISABLE
ENABLE
MR34
MR33
0
1
TELETEXT
ENABLE
DISABLE
ENABLE
Genlock Control (MR41–MR42)
These bits control the Genlock feature and timing reset of
the ADV7190/ADV7191 Setting MR41 and MR42 to Logic 0
disables the SCRESET/RTC/TR pin and allows the ADV7190/
ADV7191 to operate in normal mode.
1. By setting MR41 to zero and MR42 to one a timing reset is
2. If MR41 is set to one and MR42 is set to zero, the SCRESET/
3. If MR41 is set to one and MR42 is set to one, the SCRESET/
Active Video Line Duration (MR43)
This bit switches between two active video line durations. A zero
selects CCIR Rec. 601 (720 pixels PAL/NTSC) and a one
selects ITU-R BT. 470 standard for active video duration (710
pixels NTSC, 702 pixels PAL).
Chrominance Control (MR44)
This bit enables the color information to be switched on and off
the chroma composite, color component outputs.
Burst Control (MR45)
This bit enables the color burst to be switched on and off the
chroma and composite outputs.
Color Bar Control (MR46)
This bit can be used to generate and output an internal color
bar test pattern. The color bar configuration is 100/7.5/75/7.5
for NTSC and 100/0/75/0 for PAL. It is important to note that
when color bars are enabled the ADV7190/ADV7191 is con-
figured in a Master Timing mode. The output pins VSYNC,
HSYNC and BLANK are three-state during color bar mode.
MR33
applied, resetting the horizontal and vertical counters. This
has the effect of resetting the Field Count to Field 0.
If the SCRESET/RTC/TR pin is held high, the counters
will remain reset. Once the pin is released the counters will
commence counting again. For correct counter reset, the
SCRESET/RTC/TR pin has to remain high for at least
37 ns (one clock cycle at 27 MHz).
RTC/TR pin is configured as a subcarrier reset input and
the subcarrier phase will reset to Field 0 whenever a low-to-
high transition is detected on the SCRESET/RTC/TR pin
(SCH phase resets at the start of the next field).
RTC/TR pin is configured as a real-time control input and
the ADV7190/ADV7191 can be used to lock to an external
video source working in RTC mode. For more information see
Real-Time Control, Subcarrier Reset and Timing Reset section.
MR32
0
1
VBI OPEN
DISABLE
ENABLE
MR32
MR31
RESERVED FOR
REVISION CODE
MR31 MR30
MR30
ADV7190/ADV7191