MT312 Datasheet, PDF (44/90 Pages) Zarlink Semiconductor Inc – Satellite Channel Decoder

MT312 QPSK Demodulator
6.2.2 QPSK Status. Registers 4 - 5 (R)
NAME
ADR
B7
QPSK STAT H 04
B6
B5
B4
B3 B2 B1 B0
QPSK STATUS[15:8] (high byte)
B7: High = QPSK SNR MSB
B6: High = QPSK SNR LSB
B5: High = QPSK FR LOCK
B4: High = QPSK Timing AGC LOCK
B3: High = QPSK Timing LOCK
B2: High = QPSK Carrier LOCK
B1: High = QPSK Carrier and Timing (CT) Lock
B0: High = QPSK LOCK
Def
hex
R 00
NAME
ADR
B7
QPSK STAT L 05
B6
B5
B4
B3 B2 B1 B0
QPSK STATUS[7:0] (low byte)
B7: High = QPSK Timing sweep on
B6: High = QPSK Carrier sweep on
B5-0: Reserved
6.2.3 Symbol Rate Output. Registers 116 - 117 (R)
Def
hex
R 00
NAME
ADR
SYM RAT OP H 116
SYM RAT OP L 117
B7
B6
B5
B4
B3 B2 B1 B0
SYM RAT OP[15:8] Symbol Rate Output (high byte)
SYM RAT OP[7:0] Symbol Rate Output (low byte)
Def
hex
R 00
R 00
SYM RAT OP[15:0] These two bytes contain a positive number that is inversely proportional to the Symbol rate.
The decimation ratio index must also be read from the MONITOR register bits B[7:5] and divided by 32 to
normalise the result.
Rs = _{S-----Y---P-M---L--_--L-R--_--A-C---T--L--_-K--O----*-P-8---+1----9-8--2-1----9---2--} * 2 -DEC RATIO
Where: Rs = Symbol rate in MBaud
PLL CLK = PLL clock frequency in MHz
SYM RAT OP = value of registers 116 and 117.
DEC RATIO = MONITOR H[7:5] when MON CTRL[2:0] = 5.
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