
Preliminary Information
MT9071
55
7.2.2
MT9071 Identification Code
The MT9071 includes a status register (Table 76 - T1 & E1 ID Rev Code Data - R Address 912) which contains
an 8 bit identification code for the MT9071. This code identifies the product category, marketing revision and
the transceiver type (E1 or T1). This byte allows user software to track device revisions, and device variances
and provide system variations if necessary.
7.2.3
CS and IRQ
The MT9071 includes a CS pin for applications where a single processor is controlling numerous peripherals,
processor access can be disabled without affecting transceiver operation. Refer to the CS pin description for
details.
An IRQ pin is provided with an extensive suite of maskable interrupts. Refer to the IRQ pin description and
Section 18.0 T1 & E1 Interrupts.
7.3
ST-BUS Interface (DSTo, DSTo, CSTi, CSTo Pins)
The ST-BUS is used for PCM30 and DS0 data access only and does not carry any MT9071 control information.
The ST-BUS can be used to access any timeslot. Typically, CCS and CAS is accessed through CSTi and CSTo,
and payload data is accessed through DSTi and DSTo. Refer to the following sections:
Section 9.0 Common Channel Signaling (CCS) Operation
Section 10.0 CAS Operation
Section 11.0 Data Link Operation
Section 13.0 Transparent Mode Operation
Section 14.0 Payload Data Operation
7.3.1
ST-BUS 2.048Mb/s and 8.192Mb/s Mapping
The MT9071 provides both a 2.048Mb/s and a 8.192Mb/s backplane mode. In both modes, each of the four
transceivers operate at 2.048Mb/s; but, in 8.192Mb/s mode, and overlay is provided which maps the four
2.048Mb/s transceivers to the 8.192Mb/s backplane (see Table 12 - ST-BUS 2.048Mb/s and 8.192Mb/s
Timeslot Relationship).
7.4
Data Link Interface (RxD and RxCK Pins)
Dedicated Data Link pins are included which provide the user the option of bypassing the receive elastic buffer
and accessing timeslot 0 Data Link data with an external controller. The MT9071 provides numerous additional
methods for accessing the Data Link, refer to the Data Link sections for details.
7.5
CRC-4 and CAS Multiframe Boundary (TxMF Pins)
T
R
A
N
C
E
I
V
E
R
ST-BUS 2.048Mb/s CSTi/CSTo/CSTo/DSTo Timeslot
0-3 0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
25
26
27
28
29
30
31
ST-BUS 8.192Mb/s CSTi/CSTo/CSTo/DSTo Timeslot
0
0
4
8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 120 124
1
1
5
9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 105 109 113 117 121 125
2
2
6 10 14 18 22 26 30 34 38 42 46 50 54 58 62 66 70 74 78 82 86 90 94 98 102 106 110 114 118 122 126
3
3
7 11 15 19 23 27 31 35 39 43 47 51 55 59 63 67 68 75 79 83 87 91 95 99 103 107 111 115 119 123 127
Table 12 - ST-BUS 2.048Mb/s and 8.192Mb/s Timeslot Relationship