L64724 LSI Logic Corporation, L64724 Datasheet - Page 231

• Manufacturer Part Number: L64724
• Description: Satellite Receiver
• Manufacturer: LSI Logic Corporation

Equation B.18
Set Group 4, APR 33 to 0x2B and APR 32 to 0x8E.
Group 4, APR 34–35 – Set to 0x3334.
The value for the upper sweep limit, CAR_USWL[15:0], is set as
explained in the following paragraphs. It should be noted that the upper
sweep limit is an approximate value but the approximation to the real
sweep limit is accurate enough. Assume that the upper sweep limit
needed is + 5 MHz. The maximum sweep limit achievable is
Calculate CAR_USWL[15:0] as shown in
B.20.
Equation B.19
Equation B.20
Set Group 4 APR 35 to 0x19 and APR 34 to 0x9A.
Group 4, APR 36–37 – Set to 0xCCCC.
The value for the lower sweep limit, CAR_LSWL[15:0], is set as
explained in the following paragraphs. It should be noted that the lower
sweep limit is an approximate value but the approximation to the real
sweep limit is accurate enough. Assume that the lower sweep limit
needed is
B.21
Equation B.21
QPSK Demodulator and FEC Configuration Example: High Data Rates
CAR_SWR
CAR_USWL
CAR_USWL
CAR_LSWL
and
Equation
5 MHz. Calculate CAR_LSWL[15:0] as shown in
=
=
=
=
2
------------------------------------------------------------------------------- 2
2
----------------------------------------------
----------------------------------------- -
50.0 10
37
2
----------------------------------------------
37
37
2
B.22.
37
F s
691.2 10
F s
sweeplimit
sweeplimit
50.0 10
5 10
6
2
2
21
21
2
6
21
6
6
=
-------------------------- -
21.3 10
16
6554
1
(0x199A)
Equation B.19
6
=
11 150
and
(2B8E)
Equation
Equation
0.5 x Fs.
B-17