MT9075A
Preliminary Information
Bit
Name
Functional Description
Bit
Name
Functional Description
7
HDLC0 HDLC0 Select. If one, then HDLC0
7
6
---
Unused.
is connected to the data link on
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.
selected S bits at a rate of 4, 8, 12,
a
16 or 20 kbits/sec. If zero, HDLC0 is
deselected and all HDLC0 interrupts
are masked.
6
5
HDLC1 HDLC1 Select. If one, then HDLC1
is connected to time slot 16 in CCS
mode. If zero, HDLC1 is deselected
and all HDLC1 interrupts are
masked.
5
4
HDB3 High Density Bipolar 3 Encoding.
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.
RxTRSP Receive Transparent Mode. When
this bit is set to one, the framing
function is disabled on the receive
side. Data coming from the receive
line passes through the slip buffer
and drives DSTo with an arbitrary
alignment. When zero, the receive
framing function operates normally.
MFRF Multiframe Reframe. If one, for at
least one frame, and then cleared
the MT9075A will initiate a search
for a new signalling multiframe
position. Reframing function is
activated on the one-to-zero
transition of the MFRF bit.
4-0
---
Unused.
Table 17 - HDLC Selection Word
(Page 01H, Address 14H)
3
2
DLBK
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.
RLBK
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
MT9075A. If zero, then this feature
is disabled.
1
0
SLBK
PLBK
ST-BUS Loopback. If one, then all
time slots of DSTi are connected to
DSTo on the ST-BUS side of the
MT9075A. If zero, then this feature
is disabled. See Loopbacks section.
Payload Loopback. If one, then all
time slots received on RTIP/RRING
are connected to TTIP/TRING on
the ST-BUS side of the MT9075A
(this excludes time slot zero). If
zero, then this feature is disabled.
Table 18 - Coding and Loopback Control Word
(Page 01H, Address 15H)
4-160
MITEL [ MITEL NETWORKS CORPORATION ]
