ADV7391BCPZ Analog Devices Inc, ADV7391BCPZ Datasheet - Page 78

• Manufacturer Part Number: ADV7391BCPZ
• Description: IC ENCODER VIDEO W/DAC 32-LFCSP
• Manufacturer: Analog Devices Inc
• Type: Video Encoderr

Specifications of ADV7391BCPZ

• Applications: Set-Top Boxes, Video Players, Displays
• Voltage - Supply, Analog: 2.6 V ~ 3.46 V
• Voltage - Supply, Digital: 1.71 V ~ 1.89 V
• Mounting Type: Surface Mount
• Package / Case: 32-LFCSP
• Supply Voltage Range: 1.71V To 1.89V
• Operating Temperature Range: -40°C To +85°C
• Tv / Video Case Style: LFCSP
• No. Of Pins: 32
• Svhc: No SVHC (18-Jun-2010)
• Operating Temperature Max: 85°C
• Operating: RoHS Compliant
• Input Format: Digital
• Output Format: Analogue
• Dac Resolution: 10bit
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADV7391EBZ - BOARD EVAL FOR ADV7391 ENCODER
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADV7390/ADV7391/ADV7392/ADV7393
SD CLOSED CAPTIONING
Subaddress 0x91 to Subaddress 0x94
The ADV739x supports closed captioning conforming to the
standard television synchronizing waveform for color trans-
mission. When enabled, closed captioning is transmitted during
the blanked active line time of Line 21 of the odd fields and
Line 284 of the even fields. Closed captioning can be enabled
using Subaddress 0x83, Bits[6:5].
Closed captioning consists of a seven-cycle sinusoidal burst that
is frequency- and phase-locked to the caption data. After the
clock run-in signal, the blanking level is held for two data bits
and is followed by a Logic 1 start bit. Sixteen bits of data follow
the start bit. The data consists of two 8-bit bytes (seven data bits
and one odd parity bit per byte). The data for these bytes is
stored in SD closed captioning registers (Subaddress 0x93 to
Subaddress 0x94).
The ADV739x also supports the extended closed captioning
operation, which is active during even fields and encoded on
Line 284. The data for this operation is stored in SD closed
captioning registers (Subaddress 0x91 to Subaddress 0x92).
The ADV739x automatically generates all clock run-in signals
and timing that support closed captioning on Line 21 and Line 284.
50 IRE
40 IRE
FREQUENCY = F
REFERENCE COLOR BURST
AMPLITUDE = 40 IRE
10.5 ± 0.25µs
10.003µs
(9 CYCLES)
SC
Figure 106. SD Closed Captioning Waveform, NTSC
= 3.579545MHz
27.382µs
Rev. B | Page 78 of 108
CLOCK RUN-IN
7 CYCLES OF
0.5035MHz
12.91µs
All pixels inputs are ignored on Line 21 and Line 284 if closed
captioning is enabled.
The FCC Code of Federal Regulations (CFR) Title 47 Section
15.119 and EIA-608 describe the closed captioning information
for Line 21 and Line 284.
The ADV739x uses a single buffering method. This means that
the closed captioning buffer is only 1-byte deep. Therefore,
there is no frame delay in outputting the closed captioning data,
unlike other 2-byte deep buffering systems. The data must be
loaded one line before it is output on Line 21 and Line 284. A
typical implementation of this method is to use VSYNC to
interrupt a microprocessor, which in turn loads the new data
(two bytes) in every field. If no new data is required for
transmission, 0s must be inserted in both data registers; this is
called nulling. It is also important to load control codes, all of
which are double bytes, on Line 21. Otherwise, a TV does not
recognize them. If there is a message such as “Hello World” that
has an odd number of characters, it is important to add a blank
character at the end to make sure that the end-of-caption,
2-byte control code lands in the same field.
R
S
T
A
T
D0 TO D6
ASCII CHARACTERS
TWO 7-BIT + PARITY
BYTE 0
33.764µs
(DATA)
P
A
R
T
Y
I
D0 TO D6
BYTE 1
P
A
R
T
Y
I