MT312 Secondary Registers for Test and De-Bugging
10.2.28 Sweep PAR. Register 78 (R/W)
Def
hex
NAME
ADR
B7
B6
B5
B4
B3
B2
B1
B0
SWEEP PAR
78
SW LIM
SC [1:0]
TS NR SWEEP[2:0]
CS NR SWEE{[2:0]
R/W
49
B7-6:
SW LIM SC[1:0]
Frequency sweep limit scale.
B5-3:
B2-0:
TS NR SWEEP[2:0]
CS NR SWEEP[2:0]
10.2.29 Start up Time. Register 79 (R/W)
Def
hex
NAME
ADR
B7
B6
B5
B4
B3
B2
B1
B0
STARTUP TIME
79
STARTUP INTERVAL[7:0]
R/W
30
STARTUP INTERVAL[7:0]
10.2.30 Loss Lock Threshold. Register 80 (R/W)
Def
hex
NAME
ADR
B7
B6
B5
B4
B3
B2
B1
B0
LOSSLOCK TH
80
LOSSLOCK TH SPUR[3:0]
LOSSLOCK TH SW[3:0]
R/W
21
B7-4:
B3-0:
LOSSLOCK TH SPUR[3:0]
LOSSLOCK TH SW[3:0]
10.2.31 FEC Lock Time. Register 81 (R/W)
FEC LOCK TM (81).
Default value
32 dec.
20 hex.
FEC LOCK TM[7:0]
The number of symbol periods which the QPSK allows for the FEC to lock after achieving carrier and timing
synchronisation is given by :
FEC LOCK TM * Search factor * 65536
The parameter Search Factor is 1 if there is no code rate search and is 8 if there is a code rate search, i.e. the
QPSK allows more time for the FEC to lock in the presence of a code rate search.
If the FEC does not lock within the allotted number of symbol periods, then the QPSK resets the timing and
carrier loops and resumes the search for a QPSK signal.
68