L64704 LSI Logic Corporation, L64704 Datasheet - Page 61

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

3.6.3
Group 4,
APR 2 PLL
Parameter T,
Demodulator
and Symbol
Select
PLL Configuration Parameter T is used to configure the PLL module for
clock synthesis. This register also contains bits to configure the demod-
ulator and select the symbol format.
Read/Write: R/W
IMQ
Set to 1
QB
PLL_T
Group 4 Registers
APR
2
IMQ
D7
Set to 1
(I, -Q) Symbol Format
The bit IMQ indicates the format of the incoming symbol
stream. In BPSK mode, IMQ must be set to zero.
Set to 1
This bit must be set to 1 for proper operation.
QPSK/BPSK Format Select
Set the QB bit to specify the format of the incoming sym-
bol stream. The QB bit should be set to 0 for systems that
input a QPSK symbol pair (I, Q) once per ICLK cycle. The
QB bit should be set to 1 for BPSK input (I stream only).
PLL Configuration Parameter T
PLL_T[4:0] is one of four parameters (PLL_S, PLL_N,
PLL_T, PLL_M) that you must set to configure the PLL
module for clock synthesis. For more information see
Section
IMQ
0
1
QB
0
1
D6
Symbol Stream Format
QPSK
BPSK
4.4, “PLL Clock Generation.”
QB
D5
Symbol Format
I, Q
I, -Q
D4
D3
PLL_T[4:0]
D2
D1
D0
[4:0]
3-29
7
6
5