Advance Information
MT9074
Bit
Name
Functional Description
Bit
Name
Functional Description
2
FSI
Fs Bit Include. Only applicable
in D4 mode (not ESF or
SLC96). Setting this bit causes
errored Fs bits to be included as
framing bit errors. A bad Fs bit
will increment the Framing Error
Bit Counter, and will potentially
cause a reframe (if it is the
second bad framing bit out of 5).
The Fs bit of the receive frame
12 will only be included if
D4SECY is set low.
7
ESF
Extended
Setting
transmission and reception of
the 24 frame superframe DS1
protocol.
Super
Frame.
enables
this
bit
6
SLC96
SLC96 Mode Select. Setting
this bit enables input and output
of the Fs bit pattern on the TxDL
and
RxDL
pins.
Frame
synchronization is the same as
in the case of D4 operation. The
transmitter will insert A and B
1
0
ReFR
Reframe. Setting this bit causes
an automatic reframe.
bits every
6
frames after
synchronizing to the Fs pattern
clocked into Txdl. Receive Fs
bits are not monitored for the
Framing Bit Error Counter.
MFReFR MultiFrame Reframe. Only
applicable in D4 or SLC96
mode. Setting this bit causes an
automatic multiframe reframe.
The signalling bits are frozen
until multiframe synchronization
is achieved. Terminal frame
synchronization is not affected.
5
CXC
Cross Check. Setting this bit in
ESF mode enables a cross
check of the CRC-6 remainder
before the frame synchronizer
pulls into sync. This process
adds at least 6 milliseconds to
the frame synchronization time.
Setting this bit in D4 (not ESF)
mode enables a check of the Fs
bits in addition to the Ft bits
during frame synchronization
Table 21 - Framing Mode Select (T1)
(Page 1, Address 10H)
4 - 3
RS1- 0
Reframe Select 1 - 0. These
bits set the criteria for an
automatic reframe in the event
of framing bits errors. The
combinations available are:
RS1 - 0, RS0 - 0 = sliding
window of 2 errors out of 4.
RS1 - 0, RS0 - 1 = sliding
window of 2 errors out of 5.
RS1 - 1, RS0 - 0 = sliding
window of 2 errors out of 6.
RS1 - 1, RS0 - 1 = no reframes
due to framing bit errors.
Table 21 - Framing Mode Select (T1)
(Page 1, Address 10H)
43
MITEL [ MITEL NETWORKS CORPORATION ]
