L64777 LSI Logic Corporation, L64777 Datasheet - Page 39

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

Figure 2.16 Symbol Cutting From Bytes
Figure 2.17 Byte to Symbol Conversion
m = 4
m = 5
m = 8
m = 4
b5
m = 6
b7
b3 b2
Symbol t
b4
b6 b5
b1
b3
Symbol t
Byte N
b0
b2
b4
b3
b1
b3
Symbol t + 1
Time
b2
b0
The general control unit feeds packets of eight bytes and a valid indicator
to the convertor. Thus, the conversion is as shown in Figure 2.17.
Bytes to M-tuples Converter
b2
m = 8
b5
b1
b1
b4
b0
b0
Symbol t + 1
Bit 3
Bit 2
Bit 1
Bit 0
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
b3
b7 b6
b3 b2
Symbol t + 2
b2
b1
b5
b1
Byte N + 1
b0
b4
b0
m = 6
m = 7
b3
b3
b5
Symbol t + 3
b2
b2
b4
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Symbol t + 2
b1
b1
b3
b0
b0
b2
b7
b3
b1
Symbol t + 4
b6 b5
b2
b0 b5
Time
Byte-to-Symbol
Conversion
b1 b0
Byte N + 2
b4
b4
Symbol t + 3
b3
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
b3
b3 b2
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Symbol t + 5
b2
b2
b1
b1
b1
2-25
b0
b0
b0