MT90812
Pin Description (continued)
Pin #
64 Pin
MQFP
54
68 Pin
PLCC
14
Name
Description
Advance Information
F4o
Frame Pulse for 4.096 MHz (Output).
This is an 8 KHz output frame pulse that
indicates the start of the active ST-Bus/GCI frame. The pulse width is based upon
the period of the C4o clock.
Clock 2.048 MHz (Output).
This output is an 2.048 MHz output clock locked to
the reference input signal.
Clock 4.096 MHz (Output).
This output is an 4.096 MHz output clock locked to
the reference input signal.
Clock 10.24MHz (Output).
This output is a 10.24 MHz clock locked to the
reference input signal.
Ground.
Ringing Generator +ve Output.
This output is a 16, 20, 25 or 50 Hz square
wave.
Ringing Generator -ve Output.
Square wave output 180 degrees out of phase
with R+.
Device Reset (Input).
When 0, reset the device internal counters, registers and
tri-states STo0, STo1, EST0, EST1 and data outputs from the microport.
Internal Connection.
Tie to Vss for normal operation.
+5 Volt Power Supply.
Ground.
55
56
57
58
59
60
61
62
63
64
15
16
17
18
19
20
21
22
23
24
C2o
C4o
C10o
VSS3
R+
R-
RESET
IC
VDD
VSS4
Overview
The MT90812 Integrated Digital Switch (IDX) provides the integration of several functions required in a telecom
application. The IDX includes a digital switch for switching up to 192 x 192 channels, five conference bridges, a
DTMF/supervisory-tone bus and two digital energy detector circuits for trunk call progress tone detection.
There are two 2.048 Mbit/s Serial Links and an Expansion Bus that can operate at 2.048, 4.096 or 8.192 Mb/s.
A digital Frequency Shift Keying (FSK) transmitter, compatible to Bell 202 or CCITT V.23 1200 baud is
provided. D-Channel control is realized by microprocessor access to the MT90812. D-Channel messages are
relayed to and from the 2B+D line transceivers via the local TDM link. In D-channel Basic Receive/Transmit
mode a 32 byte buffer is provided for each of the transmit and receive directions, and these can be
independently assigned to specific D-channels. Alternatively, the HDLC controller mode can be selected,
providing an interface to the MT8952 HDLC. The HDLC controller mode provides the necessary control signals
to operate the MT8952 HDLC in external timing mode, allowing multiplexing of the MT8952 over the local TDM
links.
The MT90812 also provides an interface to the Expansion Bus capable of linking a number of MT90812
devices together directly or in a larger matrix through other digital switches. Each MT90812 can route any of
the 64 channels associated with the local TDM streams onto the Expansion Bus. Thus, system growth is easily
achieved via the addition of a MT90812 device onto the Expansion Bus. Very little hardware overhead is
required to enable cost effective system growth.
In a multi-IDX system functions including Conferencing, Tone generation, Supervisory Signal Detection, D-
channel Receiver and Transmitter, Tone Ringer and FSK Transmitter can be shared across the system. For
example, in a system consisting of four MT90812 devices, 20 three party conferences can be supported,
independent of which MT90812 the party originated. For Tone Generation, 6 programmable tones per
MT90812 translates to 24 programmable tones in a four MT90812 system, all of which can be routed to any
channel in the system.
6
MITEL [ MITEL NETWORKS CORPORATION ]
