mh89760b Mitel, mh89760b Datasheet - Page 21

• Manufacturer Part Number: mh89760b
• Description: St-bus? Family T1/esf Framer & Interface
• Manufacturer: Mitel

Preliminary Information
To control and monitor the MT8910s and the T1
interface the switch matrix operates some of its input
and output streams in message mode. This enables
the system to control all of the functions of the
MT8910s and the T1 interface through the Control
ST-BUS points, (CSTi/o).
Clock synchronization is done by the MT8941.
Phase-locked loop # 2 generates ST-BUS clocks that
are synchronized to the extracted 8kHz output from
the T1 interface. Phase-locked loop #1 generates
the transmit T1 clock synchronized to the ST-BUS
clocks, which are synchronized to the extracted T1
clock. This scheme will also allow the system to
operate in a loop timed mode.
With appropriate multiplexing a single D channel
processor can handle all 23 2B+D interfaces. If both
B channels on all 24 lines are going to be used then
it would be necessary to use two T1 trunk interfaces.
Digital Line Interface
Z
Z
T
T
MT8910
MT8910
• •
• •
• •
• •
• •
• •
• •
DSTo
DSTi
DSTo
DSTi
•
Figure 14 - ISDN Voice Data Channel Bank
•
•
•
•
DSTo
DSTi
DSTo
DSTi
MT8952
MT8952
D-Channel Processing
•
•
•
•
STi0
STo0
C4i
F0i
Switch Matrix
MT8980
P
P
5. Digital Access Cross Connect System
(DACS)
The Digital Access Cross Connect System (DACS) is
a T1 switch with 127 T1 lines as input and output
plus one T1 line that is reserved for test and
maintenance purposes. A DACS is capable of
switching any input channel on any T1 trunk to any
output channel on any T1 trunk.
There are four main blocks in Figure 15, the T1
interfaces, the switch matrix, the control matrix, and
the clock generator. The digital trunk interface is
made up of the MH89760B plus the additional
components required to interface to the transmission
line. The MH89760B handles all of the required
transmit and receive data formatting, and converts
the 1.544 MHz serial stream into ST-BUS format so
that
synchronous switch matrix.
MT8952
P
STo1
STo2
STo3
STi1
STi3
DSTo
it
DSTi
P
can
•
•
be
routed
C2i
F0i
DSTi
DSTo
CSTi0
CSTo
CSTi1
C1.5i
E8Ko
F0i
MH89760B
T1 Interface
MT8941
through
OUTA
OUTB
E8Ko
RxR
MH89760B
RxT
the
•
Equal-
MT8980
izer
C1.5
F0o
C2o
C4o
4-75