MSAN-128 Zarlink Semiconductor, Inc., MSAN-128 Datasheet - Page 8

• Manufacturer Part Number: MSAN-128
• Description: Implementing an ISDN Architecture Using the ST-BUS
• Manufacturer: Zarlink Semiconductor, Inc.

bit rates need eight bits.
channel device) allows specification of which bits in
the ST-BUS channel it uses. This capability allows
up to eight MH89500's to be connected in parallel,
submultiplexing information into a common channel.
Figure 7 shows an MH89500 connected to an
MT8930 in the TA block of the ISDN User Access
Model.
connected in parallel for submultiplexing purposes,
in a maximally integrated TA function (TA2). A TA2
allows call set up to be performed using the D-
channel. Minimal integration (TA1) means that the
ISDN has set up a semi-permanent or "hot-line"
circuit between the terminal equipment and the
packet network. The MH89500 gives its controlling
microcontroller a communication path to the DTE
through the MH89500 microprocessor port.
makes TA2 implementation much easier.
4.5 Voice Codecs
To traverse an ISDN, voice signals must be
translated to digital information using Pulse Code
Modulation (PCM) techniques and then placed into a
B-channel.
PCM components that interface voice signals to the
ST-BUS and hence, ISDN.
A-142
Figure 8 shows multiple MH89500's
G
G
S
C
R
S
C
R
T
T
I
I
Zarlink Semiconductor makes several
1489
1489
1489
1489
X.21 Port 8
X.21 Port 1
Figure 8 - Maximally Integrated TA (TA2) with Eight X.21 Ports
1488
1488
1488
1488
1488
1488
The MH89500 (a one
USERCLK
DTR
DSR
TxD
RxD
USERCLK
DTR
DSR
TxD
RxD
MH89500
MH89500
DSTo
DSTo
DSTi
DSTi
C4i
C4i
F0i
F0i
This
The base product is the MT8964/65 Voice Codec,
with programmable gain and attenuation on the I.C.
The variants of the Codec determine the digital
encoding
amplitude or A-law, true sign inverted amplitude.
The Voice Codec products can be used in both
subscriber
equipment.
working non-ISDN analog equipment with an ISDN.
The ST-BUS interface to the Voice Codec consists of
a framing pulse, a 2048 kHz clock signal, a DSTo/
DSTi port and a CSTo/CSTi port. The DST streams
carry PCM information, and the CST streams carry
control/status information.
The MT8994/5 Digital Telephone (D-phone) is a fully
integrated digital telephone I.C. designed for use in a
TE1 (Figure 7). It incorporates an on-chip Codec (µ -
law or A-law ), a tone ringer, a DTMF generator,
speaker-phone algorithm, and an interface to
standard telephony transducers.
microprocessor port for control/status requirements
(tailored to Motorola and Intel microcontrollers) and
an ST-BUS port for interfacing to either a U, or S0
interface device. The ST-BUS clock signals are a
frame pulse and a 4096 kHz clock. PCM channel
allocation is compatible with the MT8930 and the
MT8972 B1 and B2 channels in single port mode.
ST-BUS
algorithm:
DSTi
DSTo
F0b
C4b
premises
These products are useful in inter-
MT8930
PA/D
µC
µ - law,
equipment
Application Note
true
S0
sign
and
There is a
inverted
network