DS3171/DS3172/DS3173/DS3174
5 of 230
10.2.2
Sources of Clock Output Pin Signals...................................................................................................54
10.2.3
Line IO Pin Timing Source Selection...................................................................................................57
10.2.4
Clock Structures On Signal IO Pins.....................................................................................................59
10.2.5
Gapped Clocks.....................................................................................................................................60
10.3
R
ESET AND
P
OWER
-D
OWN
............................................................................................................................60
10.4
G
LOBAL
R
ESOURCES
.....................................................................................................................................63
10.4.1
Clock Rate Adapter (CLAD).................................................................................................................63
10.4.2
8 kHz Reference Generation ...............................................................................................................64
10.4.3
One Second Reference Generation.....................................................................................................66
10.4.4
General-Purpose IO Pins.....................................................................................................................66
10.4.5
Performance Monitor Counter Update Details.....................................................................................67
10.4.6
Transmit Manual Error Insertion ..........................................................................................................68
10.5
P
ER
P
ORT
R
ESOURCES
.................................................................................................................................69
10.5.1
Loopbacks............................................................................................................................................69
10.5.2
Loss Of Signal Propagation .................................................................................................................71
10.5.3
AIS Logic..............................................................................................................................................71
10.5.4
Loop Timing Mode ...............................................................................................................................74
10.5.5
HDLC Overhead Controller..................................................................................................................74
10.5.6
Trail Trace............................................................................................................................................74
10.5.7
BERT....................................................................................................................................................74
10.5.8
SCT port pins .......................................................................................................................................74
10.5.9
Framing Modes ....................................................................................................................................76
10.5.10
Line Interface Modes............................................................................................................................76
10.6
DS3/E3 F
RAMER
/ F
ORMATTER
.....................................................................................................................78
10.6.1
General Description .............................................................................................................................78
10.6.2
Features...............................................................................................................................................78
10.6.3
Transmit Formatter...............................................................................................................................79
10.6.4
Receive Framer....................................................................................................................................79
10.6.5
C-bit DS3 Framer/Formatter ................................................................................................................83
10.6.6
M23 DS3 Framer/Formatter.................................................................................................................86
10.6.7
G.751 E3 Framer/Formatter.................................................................................................................88
10.6.8
G.832 E3 Framer/Formatter.................................................................................................................90
10.7
HDLC O
VERHEAD
C
ONTROLLER
....................................................................................................................95
10.7.1
General Description .............................................................................................................................95
10.7.2
Features...............................................................................................................................................96
10.7.3
Transmit FIFO......................................................................................................................................96
10.7.4
Transmit HDLC Overhead Processor..................................................................................................97
10.7.5
Receive HDLC Overhead Processor...................................................................................................97
10.7.6
Receive FIFO.......................................................................................................................................98
10.8
T
RAIL
T
RACE
C
ONTROLLER
............................................................................................................................99
10.8.1
General Description .............................................................................................................................99
10.8.2
Features...............................................................................................................................................99
10.8.3
Functional Description........................................................................................................................100
10.8.4
Transmit Data Storage.......................................................................................................................100
10.8.5
Transmit Trace ID Processor.............................................................................................................100
10.8.6
Transmit Trail Trace Processing........................................................................................................100
10.8.7
Receive Trace ID Processor..............................................................................................................100
10.8.8
Receive Trail Trace Processing.........................................................................................................101
10.8.9
Receive Data Storage........................................................................................................................101
10.9
FEAC C
ONTROLLER
...................................................................................................................................102
10.9.1
General Description ...........................................................................................................................102
10.9.2
Features.............................................................................................................................................102
10.9.3
Functional Description........................................................................................................................102
10.10
L
INE
E
NCODER
/D
ECODER
............................................................................................................................104
10.10.1
General Description ...........................................................................................................................104
10.10.2
Features.............................................................................................................................................104
10.10.3
B3ZS/HDB3 Encoder.........................................................................................................................104