Preliminary Information

MT9173/74

9-145

select the DNIC to operate as a MASTER or SLAVE,

in DUAL or SINGLE port operation, in MODEM or

DIGITAL NETWORK mode and the order of the C

and D channels on the CD port. Table 2 provides a

description of each mode and Table 3 gives a pin

configuration according to the mode selected for all

pins that have variable functions.

These functions

vary depending on whether it is in MAS or SLV, and

whether DN or MOD mode is used.

The overall mode of operation of the DNIC can be

programmed

to be

either

a

baseband

modem

(MOD mode)

or a digital network transceiver (DN

mode).

As a baseband modem, transmit/receive

data is passed transparently through the device at 80

or 160 kbit/s by the DV port. The CD port transfers

the C-channel and D-Channel also at

80 or 160

kbit/s.

In DN mode, both the DV and CD ports operate as

ST-BUS streams at 2.048 Mbit/s.

The DV port

transfers data over pins DSTi and DSTo while on the

CD port, the CDSTi and CDSTo pins are used. The

SINGL port option only exists in DN mode.

In MOD mode, DUAL port operation must be used

and the D, B1 and B2 channel designations no

longer exist. The selection of SLV or MAS will

Table 2. Mode Definitions

Table 3. Pin Configurations

Mode

Function

SLV

SLAVE

crystal is phase locked to it to provide clocks for the entire device and are output for the external

system to synchronize to.

MAS

MASTER

which must be frequency locked. The transmit data is synchronized to the system timing with the

receive data recovered by a clock extracted from the receive data and resynchronized to the system

timing.

DUAL

DUAL PORT

and the DV port transferring the B1& B2 channels.

SINGL

SINGLE PORT - The B1& B2, C and D channels are all transferred through the DV port. The CD

port is disabled and CDSTi should be pulled high.

MOD

MODEM

through the DV port at the baud rate selected. The C-channel is transferred through the CD port

also at the baud rate and is synchronized to the CLD output.

DN

DIGITAL NETWORK

2.048 Mbits/s and the line at 80 or 160 kbits/s configured according to the applicable ISDN

recommendation.

D-C

D BEFORE C-CHANNEL

C-D

C BEFORE D-CHANNEL

ODE

OUTPUT DATA ENABLE

impedance state. This is intended for power-up reset to avoid bus contention and possible damage

to the device during the initial random state in a daisy chain configuration of DNICs. In all the other

modes of operation DV and CD ports are enabled during the appropriate channel times.

Mode

#

F0/CLD

F0o/RCK

C4/TCK

Name

Input/Output

Name

Input/Output

Name

Input/Output

0

F0

Input

F0o

Output

C4

Input

1

CLD

Output

RCK

Output

TCK

Output

2

F0

Input

F0o

Output

C4

Input

3

F0

Input

F0o

Output

C4

Input

4

F0

Output

F0o

Output

C4

Output

5

CLD

Output

RCK

Output

TCK

Output

6

F0

Output

F0o

Output

C4

Output

7

F0

Input

F0o

Output

C4

Input