msm7584c Oki Semiconductor, msm7584c Datasheet - Page 37

• Manufacturer Part Number: msm7584c
• Description: Pi /4 Shift Qpsk Modem/adpcm Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
(3) CR2 (PCMCODEC Operation Mode Settings and Transmit/Receive Gain Adjustment)
The above gain settings table shows the transmit/receive voice signal gain settings and the
transmit side gain settings for DTMF tones and other tones. Tone signal transmission is enabled
by CR4 - B6 (discussed later), and the gain setting is set to the levels shown below.
For example, if the transmit gain set value is set to +8 dB (B7, B6, B5, B4) = (0, 1, 0, 0), then the
following tones appear at the PCMSO pin.
However, the gain of the receive side tone and the gain of the side tones (path from transmit side
to receive side) are set by the CR3 register.
CR2
Initial Value
receive gain
Transmit/
–16dB
–14dB
–12dB
–10dB
DTMF tones (low group): ................................. –16 dBm0
DTMF tones (high group) and other tones: ... –14 dBm0
DTMF tones (low group): ................................. –8 dBm0
DTMF tones (high group) and other tones: ... –6 dBm0
– 8dB
– 6dB
– 4dB
– 2dB
10dB
12dB
14dB
0dB
2dB
4dB
6dB
8dB
B7, B6, B5, B4: ....... Transmit side signal gain adjustment (see Table 4)
B3, B2, B1, B0: ....... Receive side signal gain adjustment (see Table 4)
GAIN3
B7
B7
TX
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
Table 4 Receive/Transmit Gain Settings
GAIN2
B6
B6
TX
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
GAIN1
B5
B5
TX
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
GAIN0
B4
B4
TX
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
–3 dBm0 (mixed tone)
GAIN3
B3
B3
RX
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
GAIN2
B2
RX
B2
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
GAIN1
B1
B1
RX
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
MSM7584C
GAIN0
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B0
RX
B0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1