Datasheet

DS21Q50
72 of 87
Figure 19-8. Framer Synchronization Flowchart
FAS Resync
Criteria Met
Check for >=915
Out of 1000
CRC4 Word Errors
8ms
Ti me
Out
RLOS = 1
Set FASRC
(RIR.1)
CAS Resync
Criteria Met;
Set CASRC
(RIR.0)
FAS Search
FASSA = 1
FAS Sync
Criteria Met
FASSA = 0
CAS Sync
Criteria Met
CASSA = 0
If CRC4 is on
(CCR1.0 = 1)
RLOS = 1
If CAS is on
(CCR1.3 = 0)
Power Up
Increment CRC4
Sync Counter;
CRC4SA = 0
CRC4 Resync
Crit eri a Met
(RIR.2)
CAS Mul ti frame Search
(if enabled via CCR1.3)
CASSA = 1
CRC4 Mult iframe Search
(i f enabled via CCR1.0)
CRC4SA = 1
Resync if
RCR1.0 = 0
Check for FAS
Framing Error
(depends on RCR1.2)
Check for CAS
MF Word Error
Sync Declared
RLOS = 0
CRC4 Sync Cri teri a
Met; CRC4SA = 0;
Reset CRC4
Sync Counter