L64767 LSI Logic Corporation, L64767 Datasheet - Page 13

• Manufacturer Part Number: L64767
• Description: Smatv Qam Encoder
• Manufacturer: LSI Logic Corporation

Output Signals
This section describes the output signals from the L64767 to another
device such as an analog QAM modulator.
FIFOALARM
FIRSTOUT
FSTARTOUT Frame Start
SCLK
SMAENC_I[9:0]
SMAENC_Q[9:0]
L64767 SMATV QAM Encoder
FIFO Collision Detected
This alarm signal indicates the FIFO control has detected
equal pointers for read and write access. The collision is
probably caused by an unlocked external PLL-VCO
circuitry. The signal is synchronized with SCLK-driven
flip-flops for the output.
First Block of a New Sequence Out
This signal occurs together with FSTARTOUT and
indicates the head of a sync block, which has just reset
all internal sequences, as controlled by SSTARTIN.
FIRSTOUT is the acceptance of an SSTARTIN falling
edge delayed by all internal processing modules.
FSTARTOUT is driven HIGH during the first symbol in
every sync frame. The width of FSTARTOUT reflects the
number of bytes inserted by the gap parameter. A
one-cycle width indicates no additionally inserted gaps.
A width of 17 means 16 RS check bytes have been
inserted. FSTARTOUT is applied only in synchronization
word detection mode. If synchronization is forced by
FSTARTIN pulses, FSTARTOUT is constantly LOW.
Symbol Clock
SCLK is a clock output signal that is synchronous to
symbols and bytes processed internally.
Symbol I Modulation
These signals provide 10-bit digital values at the digital
filter output for D/A conversion and for analog modulation.
Symbol Q Modulation
These signals provide 10-bit digital values at the digital
filter output for D/A conversion and for analog modulation.
Output
Output
Output
Output
Output
Output
13