1.2 Operating Environment
The modulator is intended to follow either an MPEG transport stream
source (for example, a transport multiplexer) or a satellite receiver, such
as the LSI Logic L64724 (see Figure 1.1). It processes MPEG-2 system-
compliant frames at the input.
You can program the sync word and block length, and the chip can
reinsert the sync information. The device handles the MPEG-specific
transport-packet error indication (TEI) bit internally.
Figure 1.1 L64777 Operating Environment
MPEG Transport MUX
QPSK Satellite Receiver
Transmission Network
Analog QAM
Modulated I and Q
Components
MPEG Transport
Stream (Digital)
L64777
QAM
Modulator
RF
Mixer
Cable
Network
The features of the L64777 include:
•
DVB standard ETS 300 429-compliant modulation operation
Highly integrated global synchronization and clock control
On-chip VCO to support symbol rates up to 10 Msymbols/s
•
•
•
Digital NCO and interpolation mode to support operation with the
L64724
•
•
•
•
•
Four-fold Nyquist filter oversampling
Maskable interrupts for all error conditions
Individual module bypass configuration modes
I and Q baseband outputs both in digital and analog formats
2
I C-compatible serial interface for control, setup, and monitoring of
various chip parameters
•
•
•
User-controllable input synchronization schemes
16, 32, 64, 128, and 256 QAM modes
Reed-Solomon encoder
1-2
Introduction
ETC [ ETC ]
