Preliminary Information
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
Mode
SLV
MT9173/74
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
Function
SLAVE
-
The chip timebase is extracted from the received line data and the external 10.24 MHz
crystal is phase locked to it to provide clocks for the entire device and are output for the external
system to synchronize to.
MASTER
-
The timebase is derived from the externally supplied data clocks and 10.24 MHz clock
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 PORT
-
Both the CD and DV ports are active with the CD port transferring the C&D channels
and the DV port transferring the B1& B2 channels.
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.
MODEM
-
Baseband operation at 80 or 160 kbits/s. The line data is received and transmitted
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.
DIGITAL NETWORK
-
Intended for use in the digital network with the DV and CD ports operating at
2.048 Mbits/s and the line at 80 or 160 kbits/s configured according to the applicable ISDN
recommendation.
D BEFORE C-CHANNEL
-
The D-channel is transferred before the C-channel following F0.
C BEFORE D-CHANNEL
-
The C-channel is transferred before the D-channel following F0.
OUTPUT DATA ENABLE
-
When mode 7 is selected, the DV and CD ports are put in high
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.
Table 2. Mode Definitions
MAS
DUAL
SINGL
MOD
DN
D-C
C-D
ODE
Mode
#
0
1
2
3
4
5
6
7
F0/CLD
Name
F0
CLD
F0
F0
F0
CLD
F0
F0
Input/Output
Input
Output
Input
Input
Output
Output
Output
Input
Name
F0o/RCK
Input/Output
Name
C4
TCK
C4
C4
C4
TCK
C4
C4
C4/TCK
Input/Output
Input
Output
Input
Input
Output
Output
Output
Input
F0o
Output
RCK
Output
F0o
Output
F0o
Output
F0o
Output
RCK
Output
F0o
Output
F0o
Output
Table 3. Pin Configurations
9-145
MITEL [ MITEL NETWORKS CORPORATION ]
