MSAN-141 Zarlink Semiconductor, Inc., MSAN-141 Datasheet - Page 8

• Manufacturer Part Number: MSAN-141
• Description: Implementation Details of the MT8930B-31B S-T Interface
• Manufacturer: Zarlink Semiconductor, Inc.

MSAN-141
Note:
In the TE mode, the binary encoded states (see
Table 3) are as follows:
When the TE is in the deactivated state it is sending
INFO0. This can occur when NT and TE are in the
power down mode and there is no activity on the line.
As well, the TE will enter a deactivated state when
DR=1. This causes the NT to send INFO2 until the
management entity completes the deactivation
procedure.
transmitting INFO1. If this state is maintained it
implies that the NT has raised the DR and is
therefore not ready to receive information. In the
synchronized state, the TE is receiving INFO2 from
the NT and has achieved frame synchronization. If
the TE remains in the synchronized state it implies
that the NT has not synchronized to the INFO3 signal
or that the NT is not transmitting the A-bit. Finally, in
the activated state the TE transmits INFO3 while the
NT transmits INFO4 and normal data transfer can
take place.
The Diagnostic Register of a TE SNIC should be
cleared as long as the device has not achieved full
activation (state F7). This action is required to avoid
placing the device accidently in one of the test
modes that will prevent it from completing the
activation procedure. The Diagnostic Register can
be kept cleared by setting the ClrDia bit in the
Control Register to 1, and keeping this bit set until
full activation is declared by the device (IS0,
IS1=1,1).
The preceding protocol defines all ideal conditions
during activation of the line. The full state machine
A-208
Rcv. any signal
Deact. Req.
Rcv. INFO0
Rcv. INFO2
Rcv. INFO4
INFO Sent
IS0
Lost Sync
Act. Req.
0
0
1
1
--
/
BA
Sync = Synchronization
Any signal = reception of three zeros in any 48-bit
State
= No change
= Not applicable
= Bus Activity
IS1
0
1
0
1
Table 3. TE State Machine
In activation request state, the TE is
interval
- deactivated (F3)
- synchronized (F6/8)
- activation request (F4/5)
- activated (F7)
F4/5
F6/8
F6/8
F3
I0
--
--
/
/
F6/8
F6/8
F4/5
I1 or
I0 if
BA
F3
F5
--
/
/
SYNC
F6/8
I0 or
I3 if
F3
F3
F7
--
--
--
/
F6/8
F6/8
G2
F7
F3
F3
I3
--
/
incorporated on the SNIC is defined in Tables 2 and
3. Note that the letters identifying the states
correspond to those of I.430 and T1.605 specifica-
tions. The activation need only be initiated by the line
or the user at either end (i.e., NT or TE). Progression
through the state machine will be performed by the
device without user intervention. (Progression will
take place only if DR=0.) Activation or deactivation of
the bus is granted through bits 6 and 7 of the C-
channel Control Register.
Note that for the TE state machine, distinction
between states F6 and F8 when IS0, IS1=0,1 can be
done in two ways. By reading Sync bit (Sync=1 for
F6, Sync=0 for F8), or by reading INFO0 bit
(INFO0=0 for F6, INFO0=1 for F8). Similarly,
distinction between F4 and F5 when IS0, IS1=1,0
can be done by reading BA bit (BA=1 for F5, BA=0
for F4), or by reading INFO0 bit (INFO0=1 for F5,
INFO0=0 for F4).
2.3.2 Activation Times and Timers
In the ISDN, the NT and TE will require various
timing parameters to avoid tying up the network by
the overhead introduced from the various protocols.
Some of these restrictions are in the form of timers
while others will be realized in software. These limits
consist of the following:
1. A TE in the deactivated state will respond to the
2. An NT in the deactivated state must respond to
3. A TE in the activated state will respond to the
4. An NT in the activated state will respond to the
5. One last timing parameter exists within the NT to
receipt of INFO2 or INFO4 (in absence of errors)
within a 100 ms time interval. However, a TE in
the synchronized state will respond to the receipt
of INFO4 within 500 s time interval (2 frames).
the INFO1 signal within a 1 s time interval under
normal conditions. Likewise, the NT will respond
to the INFO3 with the transmission of INFO4
within 500 ms under normal conditions.
reception of INFO0 by the transmission of INFO0
within 25 ms.
reception of INFO0 or an out-of-sync condition
with the transmission of INFO2 within 25 ms.
The NT will not start sending INFO0 without a
request from the management entity.
prevent an unintentional reactivation during a
deactivation request. With reference to the state
diagram, the NT will only go to the pending
deactivation state upon expiry of timer 2 which
must be between 25 and 100 ms.
Application Note