MSM7731-02 OKI [OKI electronic componets], MSM7731-02 Datasheet - Page 33

• Manufacturer Part Number: MSM7731-02
• Description: Dual Echo Canceler & Noise Canceler with Dual Codec for Hands-Free
• Manufacturer: OKI [OKI electronic componets]

B1
B0
1 Semiconductor
Attenuator control
This bit turns ON or OFF the ATT function to prevent howling by means of attenuators (ATTsL,
ATTrL) provided in the RinL input and SoutL output of the line echo canceler.
If input is only to RinL, the ATT for SoutL (ATTsL) is activated. If input is only to SinL, or if there is
input to both SinL and RinL, the ATT for RinL input (ATTrL) is activated. The ATT value of each
attenuator is approximately 6 dB. This function is valid when the LTHR pin is in the normal mode.
Because this bit is read in synchronization with the rising edge of the SYNC signal, hold the data in the
bit for 250 µs or longer.
This bit is internally ORed with the LATT pin.
Gain controller
This bit turns ON or OFF the gain control function to control the RinL input level and prevent howling
by means of a gain controller (GainL) provided in the RinL input of the line echo canceler.
The gain controller adjusts the RIN input level when it is –10 dBm0 or above, and it has the control
range of 0 to –8.5 dB. This function is valid when the LTHR pin is in the normal mode. Because this bit
is read in synchronization with the rising edge of the SYNC signal, hold the data in the bit for 250 µs or
longer.
This bit is internally ORed with the LGC pin.
1: ATT OFF
1: GC OFF
0: ATT ON
0: GC ON
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