msm7718-01 Oki Semiconductor, msm7718-01 Datasheet - Page 29

• Manufacturer Part Number: msm7718-01
• Description: Echo Canceler With Adpcm Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
Frequencies of tones (other than DTMF signals) to be generated by the tone generator can be changed.
Tone frequencies can be changed in the Initial mode. See Figure 15-1 for procedures to change tone
frequencies. The related subaddresses are shown below.
*1
ex. When frequency = 1000 Hz, 1000 ¥ 8.192 = 9011.2 = 9011d (eliminate after the decimal
*2
ex. When wamble frequency is 8 Hz, tone frequency = 2667 Hz.
Modulation by 16 Hz sine wave
Wamble
Single tone
B4 B3 B2 B1 B0
B4 B3 B2 B1 B0
B4 B3 B2 B1 B0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Transmitted Tone Frequency = A ¥ 8.192 (A = frequency)
point) = 2333h
Wamble Frequency (Tone Transmit time) = (A/B)/2 – 1
(A = Transmitted tone frequency, B = wamble frequency)
(2667/8)/2 – 1 = 166.69 = 166d (eliminate after the decimal point) = A6h
0
0
0
0
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Subaddress 1
Subaddress 1
Subaddress 1
(Frequency 1)
(Frequency 1)
(Frequency 1)
17Dh
164h
165h
166h
167h
168h
169h
16Ah
16Bh
178h
179h
17Ah
17Bh
17Ch
17Eh
17Fh
*1
*1
*1
Subaddress 2
(Frequency 2)
Modulation by 16 Hz sine wave
8 Hz wamble tone
Transmit single tone
16Ch
16Dh
16Eh
16Fh
*1
62.5 ms
62.5 ms
Time 1
Subaddress 3
62.5 ms
Time 2
(Time 1)
170h
171h
172h
173h
*2
Subaddress 4
MSM7718-01
(Time 2)
174h
175h
176h
177h
*2
29/38