Dvd Data Processor - Samsung DVD-P360/CDM Service Manual

Circuit Operating Descriptions

13-3 DVD Data Processor

13-3-1 Outline
The Vaddis 882(highly-integrated device) includes the full front-end disc controller, back-end decoder functions as
well as the host control CPU.
The principal off-chip components include the disc drive with its optical pickup, tray, sled and spindle drivers
and motors, 16Mbits of flash MEMORY, 128Mbits of SDRAM, and the audio Digital-to-Analog converters some
applications.
In case of general disc refresh, the memory is almost filled up periodically. It is because Write rate to memory after
disc playback and signal process is faster than Read of A/V decoder. When the memory is filled, this status is report-
ed by interrupt to main micom, which controls the servo to kick back the pick-up to the previous track after mem-
orizing the last data read from disc until now. It takes some times to jump to the previous track and return to the
original(jump location) again. The memory will have an empty space because A/V decoder reads out data of mem-
ory.
When the memory has an empty space, where data can be processed and written and the pick-up correctly gets to
the original location(before kick back location) again, it reads data again avoids the interrupt of data read previ-
ously. The basic operation repeats to perform as described above.
13-3-2 Block Diagram
Fig.13-12
13-8 Samsung Electronics