B-2
Glossary of Terms and Abbreviations
C
CRC
Cyclic Redundancy Check
Bitstream error detection scheme. A check performed on
data to see if an error has occurred in transmitting,
reading, or writing the data. The result of a CRC is
typically stored or transmitted with the checked data. The
stored or transmitted result is then compared to a CRC
calculated for the data to determine if an error has
occurred.
Chroma
Chrominance
The color information portion of a signal; UV portion of
YUV color system or CbCr portion of the YCbCr color
system. Both systems are mathematically derived from
the RGB (red, blue, green) system used in television. See
YUV and YCbCr.
CMOS
Complementary Metal-Oxide Semiconductor
An electronic circuit fabricated on a silicon chip that uses
charge-based switching to provide high integration and
low power dissipation.
D
DAC
Digital-to-Analog Converter
An integrated circuit that converts a serial PCM bitstream
into a continuous analog signal. Typically used to convert
the digital audio in MPEG bitstream to analog to drive the
system speakers.
DCSQ
Display Control Sequence
DCSQ analysis uses the PTS (Presentation Time
Stamps) and STM (Start Times) stored in DVD bitstreams
to synchronize the presentation of SPUs (Subpicture
Units) with the SCR (System Clock Reference).
DCT
Discreate Cosine Transform
DMA
Direct Memory Access
Direct communication between an I/O device and
memory without CPU intervention. Used for high-speed
transfers and with busy CPUs.
DRAM
Dynamic Random Access Memory
RAM that does not require continuous power but periodic
power refreshes for data retention.