L64777 LSI Logic Corporation, L64777 Datasheet - Page 48

• Manufacturer Part Number: L64777
• Description: DVB Qam Modulator
• Manufacturer: LSI Logic Corporation

2.11.3 Default Filter Characteristics
2.12 Global Control and PLL Module
2-34
The default offset value for all four phases is 0. To shift the shifter by
default, set it to 5 bits.
Figure 2.20 shows the characteristics of the L64777 default filter.
Figure 2.21 Square-Root Raised Cosine Filter
The L64777 interface supports serial and parallel input modes at the
input interface. The global control generates the clocking for the input
and output interfaces; it also controls the data path. It contains all the
necessary logic to chain the processing units together.
Modulator Architecture
2000
4000
6000
8000
-2000
-4000
-6000
-8000
100
150
-100
-150
50
50
-50
50
0
0
0
0
0
0
0
0
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.2
Normalized Frequency (Nyquist = 1)
Normalized Frequency (Nyquist = 1)
Normalized frequency (Nyquist == 1)
Normalized frequency (Nyquist == 1)
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.5
0.5
0.5
0.5
0.6
0.6
0.6
0.6
0.7
0.7
0.7
0.7
0.8
0.8
0.8
0.8
0.9
0.9
0.9
0.9
1.0
1.0
1
1