MT8930CPR Zarlink Semiconductor, Inc., MT8930CPR Datasheet - Page 11

• Manufacturer Part Number: MT8930CPR
• Description: 4 Wire Full-duplex 2B+D (192 Kbps) Data Format ISDN S and T Subscriber Network Interface Circuit with Controllerless Mode
• Manufacturer: Zarlink Semiconductor, Inc.

TEs . All NT devices connected into the star will
receive the information transmitted by all TEs on all
branches of the star, exactly as if they were on the
same physical S-Bus.
configuration must be operating in fixed timing mode.
Refer to the description of the star configuration in
the ST-BUS section.
The SNIC has one last mode of operation called the
NT slave mode. This has the effect of operating the
SNIC in network termination mode (CK/NT pin = 1)
but having the frame structure and registers
description defined by the TE mode. This can be
used where multiple subscriber loops must carry a
fixed phase relation between each line. A typical
situation is when the system is trying to synchronize
two nodes of a synchronous network. This allows
multiple TEs to share a common ST-BUS timebase.
The synchronization of the loops is established by
using the clock signals produced by a local TE as an
input timing source to the NT slave.
NT is operating in adaptive timing
TR is the line termination resistor = 100 Ω
NT is operating in fixed timing
TR is the line termination resistor = 100 Ω
NT is operating in adaptive timing
TR is the line termination resistor = 100 Ω
NT
Figure 10 - Extended Passive Bus Configuration, up to 8 TEs can be supported
T
R
Fiure 9 - Short Passive Bus Configuration, up to 8 TEs can be supported
NT
NT
T
R
All NTs in the star
T
R
0 - 10 m
Figure 8 - Point-to-Point Configuration
TE
100 m for 75 Ω impedance cable and 200 m for 150 Ω impedance cable
TE
TE
TE
TE
TE
0-500 m
0 - 1 Km
100 - 200 m
TE
Adaptive Timing Operation
On power-up or after a reset, the SNIC in NT mode is
set to operate in fixed timing. To switch to adaptive
timing, the user should:
Switching from adaptive timing mode is completed
by resetting the Timing bit.
TE
1) set the DR bit to 1
2) set the Timing bit to 1 in the C-channel
3) wait for 100 ms period
4) proceed in using the AR and DR bits as
Control Register
desired
TE
TE
0-50 m
TE
TE
TE
TE
0 - 10 m
TE
T
R
MT8930C
T
R
TE
TE
T
R
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