MT90812 Mitel Networks Corporation, MT90812 Datasheet - Page 49

• Manufacturer Part Number: MT90812
• Description: Integrated Digital Switch (IDX)
• Manufacturer: Mitel Networks Corporation

Advance Information
17.0 Frequency Shift Keying (FSK) Transmitter
The FSK transmitter is a phase coherent FSK modulator that generates two output frequencies, representing
the ‘marks’ and ‘spaces’, of the digital data loaded into the FSK transmit memory. The ‘mark’ and ‘space
frequencies are selectable to Bell 202 or CCITT V.23 standards at 1200 baud (refer to Table 17). The FSK
transmitter output is a PCM coded signal that can be directed to any outgoing local TDM channel.
As with all outgoing channels, a gain from +3 to -27 dB in steps of 1dB, as well as - dB, may be applied to the
output of the FSK transmitter. Refer to Section 7.0 for further description of gain control. The signal output level
is -6.12dBm0 ( -Law) and -12.12 dBm0 (A-law), when the programmable gains are set at zero dB.
The FSK transmit memory is a 20-byte FIFO that is accessed at the address 07
addresses indicated in Table 20 on page 53. The FSK output is memory mapped to address 5F
Table 3 on page 14. Fig. 26 illustrates the data flow for the FSK transmitter in the MT90812.
coef
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
0
1
2
3
4
5
6
7
8
9
4000.00
2666.67
2000.00
1600.00
1333.33
1142.86
1000.00
888.89
800.00
727.27
666.67
615.38
571.43
533.33
500.00
470.59
444.44
421.05
400.00
380.95
363.64
347.83
333.33
320.00
307.69
296.30
285.71
275.86
266.67
258.06
250.00
freq
NA
CCITT V.23
Bell 202
coef
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
242.42
235.29
228.57
222.22
216.22
210.53
205.13
200.00
195.12
190.48
186.05
181.82
177.78
173.91
170.21
166.67
163.27
160.00
156.86
153.85
150.94
148.15
145.45
142.86
140.35
137.93
135.59
133.33
131.15
129.03
126.98
125.00
freq
Table 16 - Tone Ringer Programmable Frequencies
coef
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
Table 17 - FSK Signalling Frequencies
123.08
121.21
119.40
117.65
115.94
114.29
112.68
111.11
109.59
108.11
106.67
105.26
103.90
102.56
101.27
100.00
98.77
97.56
96.39
95.24
94.12
93.02
91.95
90.91
89.89
88.89
87.91
86.96
86.02
85.11
84.21
83.33
freq
coef
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
96
97
98
99
Mark
1200
1300
82.47
81.63
80.81
80.00
79.21
78.43
77.67
76.92
76.19
75.47
74.77
74.07
73.39
72.73
72.07
71.43
70.80
70.18
69.57
68.97
68.38
67.80
67.23
66.67
66.12
65.57
65.04
64.52
64.00
63.49
62.99
62.50
freq
coef
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
62.02
61.54
61.07
60.61
60.15
59.70
59.26
58.82
58.39
57.97
57.55
57.14
56.74
56.34
55.94
55.56
55.17
54.79
54.42
54.05
53.69
53.33
52.98
52.63
52.29
51.95
51.61
51.28
50.96
50.63
50.31
50.00
freq
coef
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
49.69
49.38
49.08
48.78
48.48
48.19
47.90
47.62
47.34
47.06
46.78
46.51
46.24
45.98
45.71
45.45
45.20
44.94
44.69
44.44
44.20
43.96
43.72
43.48
43.24
43.01
42.78
42.55
42.33
42.11
41.88
41.67
freq
H
. Refer to Control Register
coef
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
Space
2200
2100
41.45
41.24
41.03
40.82
40.61
40.40
40.20
40.00
39.80
39.60
39.41
39.22
39.02
38.83
38.65
38.46
38.28
38.10
37.91
37.74
37.56
37.38
37.21
37.04
36.87
36.70
36.53
36.36
36.20
36.04
35.87
35.71
freq
MT90812
H
as shown in
coef
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
35.56
35.40
35.24
35.09
34.93
34.78
34.63
34.48
34.33
34.19
34.04
33.90
33.76
33.61
33.47
33.33
33.20
33.06
32.92
32.79
32.65
32.52
32.39
32.26
32.13
32.00
31.87
31.75
31.62
31.50
31.37
31.25
freq
45