
DS26522 Dual T1/E1/J1 Transceiver 
2 of 258 
TABLE OF CONTENTS 
1.
DETAILED DESCRIPTION...............................................................................................9
M
AJOR 
O
PERATING 
M
ODES
.............................................................................................................9
FEATURE HIGHLIGHTS ................................................................................................10
G
ENERAL
......................................................................................................................................10
L
INE 
I
NTERFACE
............................................................................................................................10
C
LOCK 
S
YNTHESIZER
....................................................................................................................10
J
ITTER 
A
TTENUATOR
.....................................................................................................................10
F
RAMER
/F
ORMATTER
....................................................................................................................10
S
YSTEM 
I
NTERFACE
 ......................................................................................................................11
HDLC C
ONTROLLERS
 ...................................................................................................................12
T
EST AND 
D
IAGNOSTICS
................................................................................................................12
M
ICROCONTROLLER 
P
ARALLEL 
P
ORT
.............................................................................................12
S
LAVE 
S
ERIAL 
P
ERIPHERAL 
I
NTERFACE 
(SPI) F
EATURES
............................................................12
APPLICATIONS..............................................................................................................13
1.1
2.
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
3.
4.
SPECIFICATIONS COMPLIANCE.................................................................................14
5.
ACRONYMS AND GLOSSARY......................................................................................16
6.
BLOCK DIAGRAMS.......................................................................................................17
7.
PIN DESCRIPTIONS ......................................................................................................19
P
IN 
F
UNCTIONAL 
D
ESCRIPTION
......................................................................................................19
FUNCTIONAL DESCRIPTION........................................................................................25
M
ICROPROCESSOR 
I
NTERFACE
......................................................................................................25
8.1.1
Parallel Port Mode................................................................................................................................ 25
8.1.2
SPI Serial Port Mode............................................................................................................................ 25
8.1.3
SPI Functional Timing Diagrams ......................................................................................................... 25
8.2
C
LOCK 
S
TRUCTURE
.......................................................................................................................28
8.2.1
Backplane Clock Generation ............................................................................................................... 28
8.3
R
ESETS AND 
P
OWER
-D
OWN 
M
ODES
..............................................................................................29
8.4
I
NITIALIZATION AND 
C
ONFIGURATION
..............................................................................................30
8.4.1
Example Device Initialization Sequence.............................................................................................. 30
8.5
G
LOBAL 
R
ESOURCES
 ....................................................................................................................30
8.6
P
ORT 
R
ESOURCES
........................................................................................................................30
8.7
D
EVICE 
I
NTERRUPTS
 .....................................................................................................................30
8.8
S
YSTEM 
B
ACKPLANE 
I
NTERFACE
 ...................................................................................................32
8.8.1
Elastic Stores....................................................................................................................................... 32
8.8.2
IBO Multiplexer..................................................................................................................................... 35
8.8.3
H.100 (CT Bus) Compatibility .............................................................................................................. 36
8.8.4
Receive and Transmit Channel Blocking Registers............................................................................. 37
8.8.5
Transmit Fractional Support (Gapped Clock Mode)............................................................................ 37
8.8.6
Receive Fractional Support (Gapped Clock Mode)............................................................................. 37
8.9
F
RAMERS
......................................................................................................................................38
8.9.1
T1 Framing........................................................................................................................................... 38
8.9.2
E1 Framing........................................................................................................................................... 41
8.9.3
T1 Transmit Synchronizer.................................................................................................................... 43
8.9.4
Signaling .............................................................................................................................................. 44
8.9.5
T1 Data Link......................................................................................................................................... 48
8.9.6
E1 Data Link......................................................................................................................................... 50
8.9.7
Maintenance and Alarms ..................................................................................................................... 51
7.1
8.
8.1