®
CMOS ST-BUS™ FAMILY
MT8931B
Subscriber Network Interface Circuit
Preliminary Information
Features
•
•
•
•
•
•
•
CCITT I.430 and ANSI T1.605 S/T interface
Full-duplex 2B+D, 192 kbit/s transmission
Link activation/deactivation
D-channel access contention resolution
Point-to-point, point-to-multipoint and star
configurations
Master (NT)/Slave (TE) modes of operation
Exceeds loop length requirements
ISSUE 2
August 1993
Ordering Information
MT8931BC
28 Pin Ceramic DIP
MT8931BE
28 Pin Plastic DIP
MT8931BP
44 Pin PLCC
-40°C to +85°C
Description
The MT8931B Subscriber Network Interface Circuit
(SNIC) implements the CCITT I.430 and ANSI
T1.605 Recommendations for the ISDN S and T
reference points. Providing point-to-point and point-
to-multipoint digital transmission, the SNIC may be
used at either end of the subscriber line (NT or TE).
t
ed
ee
d n
• Complete loopback testing capabilities
sh
en ig
• On chip HDLC D-channel protocoller
m es C
data
• 8 bit Motorola/Intel microprocessor interface
om D 931
31B
• Microprocessor-controlled operation
ec ew 8
An
T89
D-channel protocoller is included and
• Mitel ST-BUS interface
HDLC
• Low power CMOS technology
t R r N MT
ll
controlled through a Motorola/Intel microprocessor
M
o fo e
fu
port.
• Single 5 volt power supply
N
Se
y for
The MT8931B is fabricated in Mitel’s CMOS process.
Applications
•
•
•
•
•
ISDN NT1
ISDN S or T interface
ISDN Terminal Adaptor (TA)
Digital sets (TE1) - 4 wire ISDN interface
Digital PABXs, Digital Line Cards (NT2)
ns
Co
lt f
u
a
or
ct
DSTi
DSTo
ST-BUS
Interface
D-channel Priority
Mechanism
LTx
S-Bus
Link
Interface
VBias
LRx
F0od
C4b
F0b
STAR/Rsto
XTAL1/NT
XTAL2/NC
Microprocessor Interface
VSS
Timing
and
Control
PLL
HDLC
Transceiver
Link
Activation
Controller
VDD
Rsti
HALF
AD0-7
R/W/WR
DS/RD
AS/ALE
CS
IRQ/NDA
Figure 1 - Functional Block Diagram
10-71
MITEL [ MITEL NETWORKS CORPORATION ]
