Preliminary Information
MT9075B
Bit
Name
Functional Description
Unused.
Bit
Name
Functional Description
7
6
---
7
TAIS
(0)
Transmit Alarm Indication Signal.
If one, an all ones signal is
transmitted. TAIS=0 for normal
operation.
MLBK Metallic Loopback. If one, then the
external RRTIP and RRING signals
are isolated from the receiver, and
TTIP and TRING are internally
connected to the receiver analog
input instead. If zero, metallic
loopback is disabled.
(0)
6
5
4
TAIS0 Transmit AIS Time Slot Zero. If
one, an all ones signal is
transmitted in time slot zero. If zero,
time slot zero functions normally.
(0)
5
4
HDB3 High Density Bipolar 3 Encoding.
TAIS16 Transmit AIS Time Slot 16. If one,
If zero, HDB3 encoding is enabled
in the transmit direction. If one, AMI
signal without HDB3 encoding is
transmitted. HDB3 is always
decoded in the receive direction.
an all ones signal is transmitted in
time slot 16. If zero, time slot
functions normally.
(0)
(0)
TE
(0)
Transmit E bits. When CRC-4
synchronization is achieved, the E-
bits transmit the received CRC-4
comparison results to the distant
end of the link, as per G.704. That
is, when zero and CRC-4
synchronization is lost, the transmit
E-bits will be zero. If one, and CRC-
MFRF Multiframe Reframe. If one, for at
least one frame, and then cleared
the MT9075B will initiate a search
for a new signalling multiframe
position. Reframing function is
activated on the one-to-zero
transition of the MFRF bit.
(0)
4
synchronization is lost the
transmit E-bits will be one.
3
2
DLBK
(0)
Digital Loopback. If one, then the
digital stream to the transmit LIU is
looped back in place of the digital
output of the receive LIU. Data
coming out of DSTo will be a
delayed version of DSTi. If zero, this
feature is disabled.
3
2
REFRM Reframe. If one for at least one
frame, and then cleared, the device
will initiate a search for a new basic
frame position. Reframing function
is activated on the one-to-zero
transition of the REFRM bit.
(0)
RLBK
(0)
Remote Loopback. If one, then all
bipolar data received on RRTIP/
RRING are directly routed to TTIP/
TRING on the PCM 30 side of the
MT9075B. If zero, then this feature
is disabled.
64KSEL 64 KHz Select. If one, a 64 KHz
signal divided down from the
extracted received 2048 kbit/sec.
clock is output on RxFP/Rx64KCK
(pin 47 in PLCC, 35 in MQFP). If
zero that pin outputs an 8 KHz
signal derived from the extracted
clock.
(0)
1
0
SLBK
(0)
ST-BUS Loopback. If one, then all
time slots of DSTi are connected to
DSTo on the ST-BUS side of the
MT9075B. If zero, then this feature
is disabled. See Loopbacks section.
1
0
DSToDE DSTo Data Enable. If zero, DSTo is
enabled. If one, DSTo will be
tristated if one of the following
conditions exists: LIU loss of signal,
loss of terminal frame sync
(SYNC=1), loss of CRC4 sync
(CRCSYN=1) or AIS.
(0)
PLBK
(0)
Payload Loopback. If one, then all
time slots received on RTIP/RRING
are connected to TTIP/TRING on
the ST-BUS side of the MT9075B
(this excludes time slot zero). If
zero, then this feature is disabled.
CSToDE CSTo Data Enable. If zero, CSTo is
enabled. If one, CSTo will be
tristated if one of the following
conditions exists: loss of multiframe
sync (MFSYNC=1), or AIS16 =1
(0)
Table 18 - Coding and Loopback Control Word
(Page 01H, Address 15H)
Table 19 - Transmit Alarm Control Word
(Page 01H, Address 16H)
33
MITEL [ MITEL NETWORKS CORPORATION ]
