L64777 A LSI Logic Corporation, L64777 A Datasheet - Page 3

• Manufacturer Part Number: L64777 A
• Description: Communications, DVB QAM Modulator
• Manufacturer: LSI Logic Corporation

Architectural Overview
Figure 3
Dispersal
Energy
ETS 300 429-Compliant Modulation Operation
(204,188)
Encoder
RS
The L64777 implements the modulator processing chain defined in
ETS 300 429. This processing chain is illustrated in
Figure 4
drives only the input synchronizing stage. The OCLK, which is four times
the QAM symbol rate, is the base of all residual processing.
L64777 DVB QAM Modulator
I
various chip parameters
User-controllable input synchronization schemes
16, 32, 64, 128, and 256 QAM modes
Reed-Solomon encoder
Frame sync byte reinsertion
Input jitter handling and Reed-Solomon gap insertion by a 128-word
circular FIFO buffer
IEEE 1149.1 JTAG interface for testing
Up to 10 Mbytes/s parallel data input
Up to 60 Mbits/s serial data input
Up to 11.25 Mbaud operation in NCO mode of operation
Easy interface to most input sources
85 ˚C ambient operation without special cooling devices
Unconstrained serial mode to allow modulation of non-MPEG data
stream
2
C-compatible serial interface for control, setup, and monitoring of
is a block diagram of the L64777 architecture. The input clock
Interleaver
Convol.
conversion
m-tuple
Byte to
Differential
Encoder
Mapping
QAM
Figure
3.
Nyquist
Square
Filter
Root
Q
I
3