
MT9072
Advance Information
66
7.2.2.1 E1 Channel Associated Signaling (CAS) Transmit from ST-BUS CSTi to PCM30
Table 25 shows the detailed bit mapping of CSTi timeslots to transmit PCM30 frames.
7.2.2.2 E1 Channel Associated Signaling (CAS) Receive from PCM30 to ST-BUS CSTo
Table 26 shows the detailed bit mapping of CSTo timeslots from receive PCM30 frames.
7.2.3
The CSIG control bit (register address Y03) must be set to one for Common Channel signaling (CCS)
operation. CCS on the transmit PCM30 link (bit positions one to eight of timeslots 15, 16 and/or 31 of every
frame) may be sourced from the ST-BUS DSTi stream or from the ST-BUS CSTi stream. If the TS15E, TS16E &
TS31E control bits (register address Y06) are zero, the transmit data will be sourced from the ST-BUS DSTi
stream timeslots 15, 16 and 31, if these bits are one, then the signaling data will be sourced from the ST-BUS
CSTi stream. Note that any combination of the TS15E, TS16E & TS31E control bits (register address Y06) may
be enabled. The CSTi source timeslots for the PCM30 timeslot 15, 16 and 31, are determined respectively by
the 15C4-15C0, 16C4-31C0 and 31C4-31C0 (register address Y07) programming bits. Table 27 shows the
E1 Common Channel Signaling (CCS) Transmit from ST-BUS CSTi and DSTi to PCM30
Frame
ST-BUS CSTi
PCM30 Transmit
Timeslot
Data Bits (B7-B0)
Timeslot
Data Bits (B1-B8)
0
0 + n
not used.
16
CAS Multiframe Alignment Signal
1m + n to
15m + n
#,#,#,#,A1, B1, C1, D1 to
#,#,#,#,A15, B15, C15, D15
16m + n
not used.
17m + n to
31m + n
#,#,#,#,A16, B16, C16, D16, to
#,#,#,#,A30, B30, C30, D30
1 to 15
as above
as above
16
A1, B1, C1, D1, A16, B16, C16, D16 to
A15, B15, C15, D15, A30, B30, C30, D30
Note 1. For 2.048Mbit/s operation, m=1 and n=0.
Note 2. For 8.192Mbit/s operation, m=4 and n =0,1,2,3 where n corresponds to the framer number (i.e. n=0=framer 0... n=3= framer 3)
Note 3. The number following the ABCD signaling bit letter designates the channel number (i.e. A30 designates channel 30).
Note 4. For these functions to be valid, CAS mode must be selected (CSIG=0 register address Y03), and the required ST-BUS
channels must be enabled (CASS=0 of register address Y90-YAF).
Note 5. # indicates data which is not transmitted.
Table 25 - Transmit PCM30 CAS Channels 1 to 30 from ST-BUS 2.048Mbit/s or 8.192Mbit/s CSTi (E1)
CAS
Frame
ST-BUS CSTo
PCM30 Receive
Timeslot
Data Bits (B7-B0)
Timeslot
Data Bits (B1-B8)
0
0 + n
1m + n to
15m + n
16m + n
17m + n to
31m + n
as above as above
not used.
1,1,1,1,A1, B1, C1, D1, to
1,1,1,1,A15, B15, C15, D15
not used.
1,1,1,1,A16, B16, C16, D16, to
1,1,1,1,A30, B30, C30, D30
16
CAS Multiframe Alignment Signal
1 to 15
16
A1, B1, C1, D1, A16, B16, C16, D16 to
A15, B15, C15, D15, A30, B30, C30, D30
Note 1. For 2.048Mbit/s operation, m=1 and n=0.
Note 2. For 8.192Mbit/s operation, m=4 and n =0,1,2,3 where n corresponds to the framer number (i.e. n=0=framer 0... n=3= framer
3).
Note 3. The number following the ABCD signaling bit letter designates the channel number (i.e. A30 designates channel 30).
Note 4. For these functions to be valid, CAS mode must be selected (CSIG=0 register address Y03).
Note 5. “1” indicates bit positions in a logic high state.
Table 26 - Receive PCM30 CAS Channels 1 to 30 to ST-BUS 2.048Mbits or 8.192Mbits CSTo (E1)