MT9072 Zarlink Semiconductor, Inc., MT9072 Datasheet - Page 41

• Manufacturer Part Number: MT9072
• Description: Octal T1-E1-J1 Framer
• Manufacturer: Zarlink Semiconductor, Inc.

Advance Information
When the device is in IMA (Inverse Mux for ATM) mode, the mapping is the S-bit followed by 24 PCM channels.
This relationship is shown in Table 3. Note that the S-bit location in the Table is indicated by the bit number;
which starts from bit 0. Hence the strict definition of ST-BUS channels is not adhered to. As in a T1 interface
the data on the DSTi/o is a bit followed by 24 channels.
When signaling information is written to the MT9072 using ST-BUS control links (as opposed to direct writes by
the microport to the on-board signaling registers), the CSTi channels corresponding to the selected DSTi
channel streams are used to transmit the signaling bits. Since the maximum number of signaling bits
associated with any channel is 4 (in the case of ABCD), only half a CSTi (bits 3 to 0) channel is required for
sourcing the signaling bits. Bit A is bit 3 from the CSTi stream, Bit B is 2, Bit C is 1, and Bit D is 0. Unused
channels and unused bits are tristate.
In T1 transparent mode, the DSTi data is transparently sent to the PCM24 channels. In transparent mode the
data on the DSTi streams will appear unaltered on the PCM24 links and data received on the PCM24 link will
pass unaltered to the DSTo streams. No signaling insertion or extraction is done in transparent mode. If the
TxSYNC control bit (address Y00) is 1 then the transmit S-bit is overwritten by channel 31 bit 0 in the 2.048
Mbit/s ST-BUS mode. In the 8.192 Mbit/s ST-BUS mode the S-bits from channels 124,125,126,127
respectively are used to override the transmit S-bit positions for Framers 0 to 3 or 4 to 7 respectively. If T1
Transparent mode and IMA mode are both selected then the S-bit and channel bits are transparently mapped
as shown in Table 3.
PCM24 Channels
ST-BUS Channels
(DSTi/o)
PCM24 Channels
ST-BUS Channels
(DSTi/o)
PCM24 Channels
ST-BUS Channels
(DSTi/o and CSTi/o)
PCM24 Channels
ST-BUS Channels
(DSTi/o and CSTi/o)
PCM24 Channels
ST-BUS
Chan(DSTi/o
and CSTi/o)
PCM24 Channels
ST-BUS
Chan(DSTi/o
and CSTi/o)
Table 2 - ST-BUS Channel vs. PCM24 Channel Relationship for 8.192 Mbit/s DST/CST Streams (T1)
Table 1 - ST-BUS vs. PCM24 Channel Relationship for 2.048 Mbit/s DST/CST Streams (T1)
Table 3 - ST-BUS vs. PCM24 to Channel Relationship for IMA DST Streams (T1)
F1/5
F2/6
F3/7
F1/5
F2/6
F3/7
F0/4
F0/4
17
64
65
66
67
17
16
1
0
1
2
3
1
0
bit
Bit
16
15
S
0
18
68
69
70
71
18
17
2
4
5
6
7
2
1
17
16
10
11
19
72
73
74
75
1
0
19
18
3
8
9
3
2
18
17
2
1
12
13
14
15
20
76
77
78
79
20
19
4
4
3
19
18
3
2
16
17
18
19
21
80
81
82
83
21
20
5
5
4
20
19
4
3
20
21
22
23
22
84
85
86
87
22
21
6
6
5
21
20
5
4
24
25
26
27
23
88
89
90
91
7
23
22
7
6
22
21
6
5
28
29
30
31
24
92
93
94
95
8
24
23
8
7
23
22
7
6
S-bit
24
124
125
126
127
9
7
32
33
34
35
x
-
9
24
23
8
7
10
25
9
x
-
10
36
37
38
39
-
9
8
10
26
11
x
-
40
41
42
43
11
-
10
9
12
27
11
x
-
12
44
45
46
47
-
11
10
13
12
28
x
-
13
48
49
50
51
-
12
11
14
13
29
x
-
14
52
53
54
55
MT9072
13
12
-
15
14
30
x
-
15
56
57
58
59
14
13
-
S-bit
16
15
31
16
60
61
62
63
15
14
-
41