L64704 LSI Logic Corporation, L64704 Datasheet - Page 200

• Manufacturer Part Number: L64704
• Description: Satellite Decoder Technical Manual 5/97
• Manufacturer: LSI Logic Corporation

B-12
Group 4, APR 27 – The recommended value for CAR_THSL[7:0] is 31
when FP_LOCK_LEN (Group 4, APR 35) is set to 0. Otherwise, set it
according to the following table:
FP_LOCK_LEN
Set Group 4, APR 27 to 0x1F.
Group 4, APR 28 – The recommended starting point for
CAR_SWR[7:0] is 33. Experiment with other values to optimize
performance.
Set Group 4, APR 28 to 0x21.
Group 4, APR 29-30 – The recommended value for CAR_USWL[13:0]
is 12301, assuming that the prescaler divides the frequency of the carrier
VCO by 32 and that jitter is 1 MHz.
CAR_USWL = ((479.5 + 1) / 32) x ((8 x 1024) / 10) = 12301
Set APR 29 to 0x30 and APR 30 to 0x0D.
Group 4, APR 31-32 – Set CAR_LSWL to 12250, based on the follow-
ing equation:
CAR_LSWL = ((479.5 – 1) / 32) x ((8 x 1024) / 10) = 12250
Set APR 31 to 0x2F and APR 32 to 0xDA.
L64704 Application Notes
0
1
CAR_THSL[7:0]
31
72
Signal to Noise Ratio
Low Eb/No
High Eb/No