msm7718-01 Oki Semiconductor, msm7718-01 Datasheet - Page 27

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

¡ Semiconductor
(5) CR4 (Adjustment of tone generator gain)
B7, 6, 5, 4 ...... Transmit side gain adjustment for the tone generator [ATTtgtx] (see Table 4)
B3, 2, 1, 0 ...... Receive side gain adjustment for the tone generator [ATTtgrx] (see Table 5)
Settings of Table 5 are made in relation to the following tone levels:
For example, when bits B3, B2, B1, and B0 are set to “1, 1, 1, 1” (–6 dB), the PCMLNO pin outputs a
tone of the following levels:
The default value change command enables the gain adjustment by –1 dB step.
Writing “13CAh” into the address 00D8h adds a gain of –1 dB to the values in the above table. The
default value is “1634h”.
CR4
Initial value
B7
B3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
B6
B2
DTMF tone (Low frequency group)
DTMF tone (High frequency group) and other tone
DTMF tone (Low frequency group)
DTMF tone (High frequency group) and other tone
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
B5
B1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Table 4 Setting of Transmit Side Gain of Tone Generator
Table 5 Setting of Receive Side Gain of Tone Generator
TX TONE
GAIN3
B7
0
B4
B0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Tone generator gain
Tone generator gain
TX TONE
GAIN2
B6
0
–36 dB
–34 dB
–32 dB
–30 dB
–28 dB
–26 dB
–24 dB
–22 dB
–36 dB
–34 dB
–32 dB
–30 dB
–28 dB
–26 dB
–24 dB
–22 dB
TX TONE
GAIN1
B5
0
TX TONE
GAIN0
B7
B3
B4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
B6
B2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
RX TONE
GAIN3
B3
0
B5
B1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
: –2 dBm0
: 0 dBm0
: –8 dBm0
: –6 dBm0
RX TONE
GAIN2
B4
B0
B2
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Tone generator gain
Tone generator gain
RX TONE
GAIN1
B1
0
MSM7718-01
–20 dB
–18 dB
–16 dB
–14 dB
–12 dB
–10 dB
–20 dB
–18 dB
–16 dB
–14 dB
–12 dB
–10 dB
–8 dB
–6 dB
–8 dB
–6 dB
RX TONE
GAIN0
27/38
B0
0