Data sheet
MH89790B
attenuation and Alternate Digit Inversion are disabled. It
should be noted that the control word for a given
information channel is input one timeslot early, i.e.,
channel 0 of CSTi0 controls channel 1 of DSTi. Channels
15 and 31 of CSTi0 contain Master Control Words 1 and 2
(MCW1, MCW2) which are used to set up the interface
feature as seen by the respective bit functions of Tables 3
and 4.
Control Input 1 (CSTi1)
Control ST-BUS input stream number 1 (CSTi1) contains
the synchronization information and the A, B, C & D
BIT
NAME
DESCRIPTION
7,
6,
A(N),
B(N),
Transmit Signalling Bits for Channel N: These bits are transmitted on the CEPT 2048 kbit/s link in bit
positions 1 to 4 of timeslot 16 in frame N, and are the A, B, C and D signalling bits associated with
telephone channel N. The value of N lies in the range 1 to 15 and refers to the channel on the CSTi1
channel from which the bits are sourced, the telephone channel with which the bits are associated and the
frame on the CEPT link on which the bits are transmitted. For example, the bits input on the CSTi1 pin on
channel 3 are associated with telephone channel 3, which is timeslot 3 of the CEPT link, and are
transmitted on bits positions 1 to 4 of timeslot 16 in frame 3 of each multiframe on the CEPT link . If bits B,
C or D are not used they should be given the values ‘1, 0‘ and ‘1‘ respectively. The combination ‘0000‘ for
ABCD bits should not be used for telephone channels 1 to 15 as this would interfere with multiframe
alignment.
5
C(N)
& 4
& D(N)
3,
2,
A(N+15),
B(N+15),
C(N+15)
Transmit Signalling Bits for Channel N+15: These bits are transmitted on the CEPT 2048 kbit/s link in
bit positions 5 to 8 of timeslot 16 in frame N, and are the A, B, C and D signalling bits associated with
telephone channel N+15. The value of N lies in the range 1 to 15 and refers to both the channel on the
CSTi1 stream where the bits are supplied and the frame on the CEPT link on which the bits are transmitted,
and indirectly indicates the telephone channel with which the bits are are associated. For example, the bits
input on the CSTi1 pin on channel 3 are associated with telephone channel 18, which is timeslot 19 of the
CEPT link, and are transmitted in bits positions 5 to 8 of timeslot 16 in frame 3 of each multiframe on the
CEPT link .
1
& 0
& D(N+15)
Table 6 Channel Associated Signalling: Data Format for CSTi1 Channels 1 to 15
BIT
7
NAME
IU0
DESCRIPTION
International Use 0: When CRC is disabled, this bit is transmitted on the CEPT 2048 kbit/s link in bit
position 1 of timeslot 0 of frame-alignment frames . It is reserved for international use and should be kept
at ‘1’ when not used. If CRC is enabled, this bit is not used.
6-0
FAF2-8
Transmit Frame Alignment Signal Bits 2 to 8: These bits are transmitted on the CEPT 2048 kbit/s link
in bit positions 2 to 8 of timeslot 0 of frame-alignment frames. These bits form the frame alignment signal
and should be set to ‘0011011‘.
Table 7 Frame-Alignment Signal: Data Format for CSTi1 Channel 16
BIT
7
NAME
IU1
DESCRIPTION
International Use 1: When the CRC is disabled and SiMUX bit in MCW3 is disabled, this bit is
transmitted on the CEPT 2048 kbit/s link in bit position 1 of timeslot 0 of non-frame-alignment frames . It
is reserved for international use and should be kept at ‘1‘ when not used. If CRC is enabled and SiMUX is
disabled, this bit is transmitted in bit 1 of timeslot 0 for frame 13 and 15. If both CRC and SiMUX are
enabled, then this bit is not used.
6
5
NFAF
ALM
Transmit Non-Frame Alignment Bit: This bit is transmitted on the CEPT 2048 kbit/s link in bit position
2 of timeslot 0 of non-frame-alignment frames . In order to differentiate between frame-alignment frames
and non-frame-alignment frames, this bit should be kept at ‘1‘.
Non-Frame Alignment Alarm: This bit is transmitted on the CEPT 2048 kbit/s link in bit position 3 of
timeslot 0 of non-frame-alignment frames . It is used to signal an alarm to the remote end of the CEPT link.
The bit should be set to ‘1‘ to signal an alarm and should be kept at ‘0‘ under normal operation.
4-0
NU1-5
National Use: These bits are transmitted on the CEPT 2048 kbit/s link in bit positions 4 to 8 of timeslot 0
of non-frame-alignment frames . These bits are reserved for national use, and on crossing international
borders they should be set to ‘1‘.
Table 8 Non-Frame-Alignment Signal: Data Format for CSTi1 Channel 17
Zarlink Semiconductor Inc.
9
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
