MH89790B
BIT
7
6
Preliminary Information
NAME
(N/A)
LOOP16
Keep at ‘1‘ for normal operation.
DESCRIPTION
Channel 16 Loopback:
If ‘1‘, then timeslot 16 on the transmitted CEPT 2048 kbit/s link is
looped internally to replace the data received on timeslot 16. If ‘0,‘ then this function is
disabled.
This function only operates if frame synchronization is received from the CEPT link and only a
single timeslot can be looped within the frame.
Keep at ‘1‘ for normal operation.
Signalling Bit Debounce:
If ‘1‘, then no debouncing is applied to the received A, B, C or D
signalling bits. If ‘0‘, then the received A, B, C or D signalling bits are debounced for between
6 and 8 ms.
5,4
3,2,
1
&0
(N/A)
NDBD, NDBC,
NDBB
& NDBA
Table 3. Master Control Word 1 (MCW1): Data Format for CSTi0 Channel 15
BIT
7
6
5
NAME
(N/A)
(N/A)
CCS
Keep at ‘1‘ for normal operation.
Keep at ‘0‘ for normal operation.
DESCRIPTION
Common Channel Signalling:
If 1, then the MH89790B operates in its common channel
signalling mode. Channel 16 on the DSTi pin is transmitted on timeslot 16 of the CEPT link, and
timeslot 16 from the received CEPT link is output on channel 16 on the DSTo pin. Channel 15 on
the CSTi0 pin contains the information for the control of timeslot 16. Channels 0 to 15 on CSTi1
and CSTo are unused.
If ‘0‘, the device is in channel associated signalling mode where channel 16 is used to transmit
the ABCD signalling bits.
8kHz Select:
If ‘1‘, then an 8 kHz signal synchronized to the received CEPT 2048 kbit/s link is
output on the E8Ko pin. This feature is only valid when frame synchronization is received from
the CEPT link.
If ‘0‘, then the E8Ko pin goes into its high impedance state.
Transmit Alarm Indication Signal:
If ‘1‘, then an all 1’ s alarm signal is transmitted on all timeslots.
If ‘0‘, then the timeslots functions normally.
Transmit Timeslot 16 Alarm Indication Signal:
If ‘1‘, then an all 1’s alarm signal is transmitted on timeslot 16.
If ‘0‘, then timeslot 16 functions normally.
External Control:
If ‘1‘, then the XCtl pin is driven high.
If ‘0‘, then the XCtl pin is driven low.
(unused)
4
8kHzSEL
3
TXAIS
2
TXTS16AIS
1
XCtl
0
(N/A)
Table 4. Master Control Word 2 (MCW2): Data Format for CSTi0 Channel 31
BIT
7-4
NAME
MA1-4
DESCRIPTION
Transmit Multiframe Alignment Bits 1 to 4:
These bits are transmitted on the CEPT 2048
kbit/s link in bit positions 1 to 4 of timeslot 16 of frame 0 of the multiframe. They should be kept at
‘0‘ to allow multiframe alignment to be detected.
This bit is transmitted on the CEPT 2048 kbit/s link in bit position 5 of timeslot 16 of frame 0 of the
multiframe. It is a spare bit which should be kept at ‘1‘ if unused.
This bit is transmitted on the CEPT 2048 kbit/s link in bit position 6 of timeslot 16 of frame 0 of the
multiframe. It is used to indicate the loss of multiframe alignment to the remote end of the link. A
‘1‘ on this bit is the signal that multiframe alignment on the received link has been lost. A ‘0’
indicates that multiframe alignment is detected.
These bits are transmitted on the CEPT 2048 kbit/s link in bit positions 7 and 8 respectively, of
timeslot 16 of frame 0 of the multiframe. They are spare bits which should be kept at ‘1‘ if unused.
3
2
X1
Y
1,0
X2,X3
Table 5. Multiframe Alignment Signal:Data Format for CSTi1Channel 0 on the Transmitted CEPT Link
4-194
MITEL [ MITEL NETWORKS CORPORATION ]
