ADV601
–23–
REV. 0
Video Formats—CCIR-656
The ADV601 supports a glueless video interface to CCIR-656
devices when the Video Format is programmed to CCIR-656
mode. CCIR-656 requires that 4:2:2 data (8 or 10 bits per com-
ponent) be multiplexed and transmitted over a single 8- or 10-bit
physical interface. A 27 MHz clock is transmitted along with the
data. This clock is synchronous with the data. The color space of
CCIR-656 is YCrCb.
When in master mode, the CCIR-656 mode does not require
any external synchronization or blanking signals to accompany
digital video. Instead, CCIR-656 includes special time codes in
the stream syntax that define horizontal blanking periods, verti-
cal blanking periods, and field synchronization (horizontal and
vertical synchronization information can be derived). These
time codes are called End-of-Active-Video (EAV) and Start-of-
Active-Video (SAV). Each line of video has one EAV and one
SAV time code. EAV and SAV have three bits of embedded
information to define HSYNC, VSYNC and Field information
as well as error detection and correction bits.
VCLK is driven with a 27 MHz, 50% duty cycle clock which is
synchronous with the video data. Video data is clocked on the
rising edge of the VCLK signal. When decoding, the VCLK
signal is typically transmitted along with video data in the
CCIR-656 physical interface.
Electrically, CCIR-656 specifies differential ECL levels to be
used for all interfaces. The ADV601, however, only supports
unipolar, TTL logic thresholds. Systems designs that interface
to strictly conforming CCIR-656 devices (especially when inter-
facing over long cable distances) must include ECL level shifters
and line drivers.
The functionality of HSYNC, VSYNC and FIELD Pins is
dependent on three programmable modes of the ADV601:
Master-Slave Control, Encode-Decode Control and 525-625
Control. Table IX summarizes the functionality of these pins in
various modes.
Table IX. CCIR-656 Master and Slave Modes HSYNC, VSYNC, and FIELD Functionality
HSYNC, VSYNC and FIELD Master Mode (HSYNC, VSYNC Slave Mode (HSYNC, VSYNC
Functionality for CCIR-656 and FIELD Are Outputs) and FIELD Are Inputs)
Encode Mode (video data is input Pins are driven to reflect the states of the Undefined—Use Master Mode
to the chip) received time codes: EAV and SAV. This
functionality is independent of the state of
the 525-625 mode control. An encoder is
most likely to be in master mode.
Decode Mode (video data is output Pins are output to the precise timing definitions Undefined—Use Master Mode
from the chip) for CCIR-656 interfaces. The state of the pins
reflect the state of the EAV and SAV timing
codes that are generated in the output video data.
These definitions are different for 525 and 625 line
systems. The ADV601 completely manages the
generation and timing of these pins.
Video Formats—Philips Video
Philips video format requires 4:2:2 data (8 bits per component)
be transmitted over a two “lane” 16-bit physical interface. A
27 MHz clock is transmitted along with the data. This clock is
synchronous with the data and is running at twice the transfer
rate of the interface. The color space is YUV. VCLK is driven
with a 27 MHz 50% duty cycle clock, which is synchronous with
the video data. Philips video format requires external synchroni-
zation and blanking signals to accompany digital video. These
signals are VSYNC, HSYNC, CREF and FIELD. In general,
when the ADV601 is configured as an encoder, these signals will
all be inputs. When the ADV601 is configured as a decoder,
these signals will be outputs. There are special cases for this
described in Table X.
The functionality of HSYNC, VSYNC, and FIELD pins is depen-
dent on three programmable modes of the ADV601: Master-Slave
Control, Encode-Decode Control, and 525-625 Control. Table X
summarizes the functionality of these pins in various modes.
Table X. Philips Video Master and Slave Modes HSYNC, VSYNC and FIELD Functionality
HSYNC, VSYNC and FIELD Master Mode (HSYNC, VSYNC, Slave Mode (HSYNC, VSYNC,
Functionality for Philips Video CREF and FIELD Are Outputs) CREF and FIELD Are Inputs)
Encode Mode (video data is input The ADV601 completely manages the generation These pins are used to control the
to the chip) and timing of these pins. The device driving the blanking of video and sequencing
ADV601 video interface must use these outputs to of the YSC, CSC, and LC counters.
remain in sync with the ADV601. It is expected that
this combination of modes would not be used frequently.
Decode Mode (video data is output The ADV601 completely manages the These pins are used to control the
from the chip) generation and timing of these pins. blanking of video and sequencing
of the YSC, CSC, and LC counters.
