MT9173/74

Data Sheet

4

Zarlink Semiconductor Inc.

Figure 4 - DV Port - 160 kbit/s (Modes 2, 3, 6)

Functional Description

The MT9173 and MT9174 are multifunction devices capable of providing high speed, full duplex digital transmission

at up to 160 kbit/s over a twisted wire pair. They use adaptive echo-cancelling techniques and transfer data in a

format compatible to the ISDN basic rate. Several modes of operation allow an easy interface to digital

telecommunication networks including PCS wireless base stations, smart telephone sets, workstations, data

terminals and computers. The device supports the 2B+D channel format (two 64 kbit/s B-channels and one

16 kbit/s D-channel) over two wires as recommended by the CCITT. The line data is converted to and from the ST-

BUS format on the system side of the network to allow for easy interfacing with other components such as the S-

interface device in an NT1 arrangement, or to digital PABX components.

Smart telephone sets with data and voice capability can be easily implemented using the MT9173/74 as a line

interface. The device’s high bandwidth and long loop length capability allows its use in a wide variety of sets. This

can be extended to provide full data and voice capability to the private subscriber by the installation of equipment in

both the home and central office or remote concentration equipment. Within the subscriber equipment the

MT9173/74 would terminate the line and encode/ decode the data and voice for transmission while additional

electronics could provide interfaces for a standard telephone set and any number of data ports supporting standard

data rates for such things as computer communications and telemetry for remote meter reading. Digital

workstations with a high degree of networking capability can be designed using the DNIC for the line interface,

offering up to 160 kbit/s data transmission over existing telephone lines. The MT9173/74 could also be valuable

within existing computer networks for connecting a large number of terminals to a computer or for intercomputer

links. With the DNIC, this can be accomplished at up to 160 kbit/s at a very low cost per line for terminal to

computer links and in many cases this bandwidth would be sufficient for computer to computer links.

Figure 1 shows the block diagram of the MT9173/74. The DNIC provides a bidirectional interface between the DV

(data/voice) port and a full duplex line operating at 80 or 160 kbit/s over a single pair of twisted wires. The DNIC has

three serial ports. The DV port (DSTi/Di, DSTo/Do), the CD (control/data) port (CDSTi/CDi, CDSTo/CDo) and a line

information received from both the DV and CD ports and put it onto the line. At the same time, the data received

from the line must be split into the various channels and directed to the proper ports. The usable data rates are 72

F0

C4

DSTi

DSTo

F0o

Channel Time 0

Channel Time 16