mt9074ap1 Zarlink Semiconductor, mt9074ap1 Datasheet - Page 28

• Manufacturer Part Number: mt9074ap1
• Description: T1/e1/j1 Single Chip Transceiver With Wide Dynamic Range Liu
• Manufacturer: Zarlink Semiconductor

E1 Digital Interface
PCM30 (E1) basic frames are 256 bits long and are transmitted at a frame repetition rate of 8000 Hz, which results
in an aggregate bit rate of 256 bits x 8000/sec = 2.048 Mbits/sec. The actual bit rate is 2.048 Mbits/sec +/-50 ppm
encoded in HDB3 format. The HDB3 control bit (page 01H, address 15H, bit 5) selects either HDB3 encoding or
alternate mark inversion (AMI) encoding. Basic frames are divided into 32 time slots numbered 0 to 31, see Figure
34. Each time slot is 8 bits in length and is transmitted most significant bit first (numbered bit 1). This results in a
single time slot data rate of 8 bits x 8000/sec. = 64 kbits/sec.
It should be noted that the Zarlink ST-BUS also has 32 channels numbered 0 to 31, but the most significant bit of an
eight bit channel is numbered bit 7 (see Zarlink Application Note MSAN-126). Therefore, ST-BUS bit 7 is
synonymous with PCM30 bit 1; bit 6 with bit 2: and so on (Figure 34).
PCM30 time slot 0 is reserved for basic frame alignment, CRC-4 multiframe alignment and the communication of
maintenance information. In most configurations time slot 16 is reserved for either Channel Associated Signaling
(CAS or ABCD bit signaling) or Common Channel Signaling (CCS). The remaining 30 time slots are called
channels and carry either PCM encoded voice signals or digital data. Channel alignment and bit numbering is
consistent with time slot alignment and bit numbering. However, channels are numbered 1 to 30 and relate to time
slots as per Table 10.
Frame #
10
12
13
14
15
16
17
18
19
20
21
22
23
24
11
1
2
3
4
5
6
7
8
9
Ft
1
0
1
0
1
0
1
0
1
0
1
0
Fs
0
0
0
1
1
1
0
0
0
1
1
1
Notes Frame #
R
e
n
h
o
n
z
a
o
n
d
a
a
s
y
c
r
t
t
i
i
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Table 9 - SLC-96 Framing Structure(T1)
Ft
1
0
1
0
1
0
1
0
1
0
1
0
Zarlink Semiconductor Inc.
Fs Notes Frame #
X
X
X
X
X
X
X
X
X
X
X
S
MT9074
28
C
B
o
n
e
n
a
o
F
e
d
c
s
r
r
t
t
i
l
i
t
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
Ft
1
0
1
0
1
0
1
0
1
0
1
0
Fs
S
S
C
C
C
A
A
S
L
L
L
L
C = Maintenance Field Bits
L = Line Switch Field Bits
A = Alarm Field Bits
S = Spoiler Bits
S = Spoiler Bits
Notes
Data Sheet