L64777 LSI Logic Corporation, L64777 Datasheet - Page 114

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

B-4
When the input to the L64777 is from the L64724 for a satellite of
selected center frequency and baud rate, the parameters to be
programmed into the L64777 for 64 QAM are:
After synchronization:
Note that the PLL_SET bit (Register 1) must be set before downloading
any counter parameters, and it must be cleared after completion. This
applies to Mode 2 programming.
PLL Divider Settings and L64724/34 Connection
Operational Mode = NCO mode (Mode 2)
Block Length = 188 bytes
GAP = 16 bytes
I-Counter = 6 (0x6)
O-Counter = 32 (0x20)
OCLK = Baud rate x 2 x 3/4 x oversampling x 1/(symbol size)
SCLK = OCLK/4
where:
oversampling = 4
symbol size = 6 for QAM mode of 64 (log of QAM level to
base 2)