Directview LCD Training 67 CableCARD
CABLECARD
DCR ARCHITECTURE
Inband
6 MHz
OOB
QPSK
Tuner
QAM
QPSK
Demod
NTSC
CPU
- User I/F
- Functions
-Apps
- VBI decode
-etc.
Multimedia
Processor
-NTSC coder
-Graphics
processor
CA
Decrypt
& CP
Encrypt
(POD)
CP Decrypt
& Demux
A/V
Decode
1394A + CP
AVD
SPTS
AC-3 Out
L/R Out
S-Video Out
Ch-3/4 Out
Video Out
Cable
In
HDMI/DVI Out
The OOB (Out Of Band) tuner runs all the time, locked to the frequency which it is given by the
Cablecard. The data from the Headend should be on this frequency. If it is not, the tuner wil not see
the data nor will the Cablecard. EX: If the cablecard tells the unit to tune to 104.20Mhz. The unit will
tune to 104.20Mhz and not search for other frequencies. If the MSO (Multi System Operator) has the
cards prgrammed to give the unit a list of frequencies, the unit will search that list of frequencies to
find the data and then lock. If the data is on 104.25Mhz, neither the unit nor card can get the data
needed to receive a channel list and an authorization list , the CP and decrypt data. As a result, the
unit will not be allowed to tune premium channels.
HOST-CABLECARD INTERFACE
The data communication to and from the Cablecard and unit is encrypted. The Host (Unit) and POD
(Cablecard) share a buffer so that the data from the headend is never lost. Some of the buffer is in
the POD and some is in the host.The authorization list, CP data, Decrypt data and some other data is
updated every 10 -20 seconds. This allows the cable company to add, remove, and rearrange channels
as needed and the Cablecard is updated within seconds without the customer having to run EZ Scan
to load new channels added to their lineup. The data from the headend is at regular intervals and can
fluctuate in timing. This causes the data to flow at a higher rate at times and a lower rate at other
times depending on other tasks the headend is performing on the system. The comunication between
the POD and host is a two way relationship. While the communication between the Cablecard and
headed is only one way, from the headend to the card.
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