The default offset value for all four phases is 0. To shift the shifter by
default, set it to 5 bits.
2.11.3 Default Filter Characteristics
Figure 2.20 shows the characteristics of the L64777 default filter.
Figure 2.21 Square-Root Raised Cosine Filter
50
50
0
0
-50
−50
−100
-100
−150
-150
0
0
0.1
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.9
1.0
1
0.2 0.3 0.4
0.5 0.6 0.7 0.8
Normalized Frequency (Nyquist = 1)
Normalized frequency (Nyquist == 1)
0
0
-2000
−2000
−4-4000000
−6000
-6000
−8000
-8000
0
0.1
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.9
1.0
1
0
0.2 0.3 0.4
0.5 0.6 0.7 0.8
Normalized Frequency (Nyquist = 1)
Normalized frequency (Nyquist == 1)
2.12 Global Control and PLL Module
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.
2-34
Modulator Architecture
ETC [ ETC ]
