CLC031VEC National Semiconductor, CLC031VEC Datasheet - Page 13

• Manufacturer Part Number: CLC031VEC
• Description: IC DESERIAL/DESCRMBLR VID 64TQFP
• Manufacturer: National Semiconductor
• Type: Descrambler/Deserializerr

Specifications of CLC031VEC

• Applications: SDTV/HDTV
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *CLC031VEC

Device Operation
Ancilliary Data Functions
The CLC031 can recover Ancilliary Data from the serial
data stream. This ancilliary data and related control charac-
ters are defined in the relevant SMPTE standards and may
reside in the horizontal and vertical blanking intervals. The
data can consist of different types of message packets in-
cluding audio data. The serial ancilliary data space must be
formatted according to SMPTE 291M. The CLC031 sup-
ports ancilliary data in the chrominance channel (C’r/
C’b) only for high-definition operation. Ancilliary data for
standard definition follows the requirements of SMPTE
125M.
The Ancilliary Data FIFO is sized to handle a maximum
length ANC data Type 1 or Type 2 packet without the ANC
Flag, 259 words. Defined in SMPTE 291M, the packet con-
FIGURE 2. Control Data Read Timing (2 read and 1 write cycle shown)
(Continued)
FIGURE 3. Control Data Write Timing
13
sists of the Ancilliary Data Flag, a 3-word Data ID and Data
Count, 255 8- or 10-bit User Data Words and a Checksum.
The design of the CLC031 Ancilliary Data FIFO also allows
storage of up to 8 shorter length messages with total length
not exceeding 259 words including all ID information. Ancil-
liary Data is copied from the data stream into the Ancilliary
Data FIFO. The parallel ancilliary data will still be present in
the parallel chroma output DV[9:0]. Ancilliary flag informa-
tion is not extracted into the FIFO.
Copying of ANC data from the video data into the FIFO is
controlled by the ANC Mask and ANC ID bits in the control
registers. A system of flags, ANC FIFO Empty, ANC FIFO
90% Full, ANC FIFO Full and ANC FIFO Overrun are used
to monitor FIFO status. The details and functions of these
and other control words are explained later in this datasheet.
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