msm7718-01 Oki Semiconductor, msm7718-01 Datasheet - Page 32

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

¡ Semiconductor
B7 ... Acoustic echo canceler through-mode control bit
B6 ... Not used
B5 ... Selects whether or not to clear the coefficient of the adaptive FIR filter (AAFF) for the
B4 ... Howling detector (HD) ON/OFF control
B3 ... Turns ON or OFF the center clip function which forcibly sets the Sout output of the acoustic
B2 ... Selects whether or not to update the coefficient of the adaptive FIR filter (AAFF) for the
B1 ... Turns ON or OFF the ATT function which prevents howling from occurring by means of
B0 ... Turns ON or OFF the gain control function which controls the RinA input level and
(10) CR9 : Reserved (Setting of acoustic echo canceler operating mode)
CR9
Initial value
*1 Names of control pins used in the MSM7602
In this mode, RinA data and SinA data are through-output to RoutL and SoutL respectively.
1: Through mode 0: Normal mode (echo cancellation)
acoustic echo canceler.
1: Resets the coefficient 0: Normal operation
echo canceler to a minimum positive value when it is –57 dBm0 or less.
1: Center clip function ON
2: Center clip function OFF
acoustic echo canceler.
1: Coefficient Fixed mode
0: Normal mode (updates the coefficient.)
attenuators ATTrA and ATTsA provided for the RinA input and the SoutA output of the
acoustic echo canceler.
When a signal is input to RinA only, the attenuator ATTsA of the SoutA output is activated.
When a signal is input to SinA only or to both SinA and RinA, the attenuator ATTrA of the RinA
input is activated. Their ATT values are both about 6 dB.
1: ATT OFF
0: ATT ON
prevents howling from occurring by the gain controller (GainA) for the RinA input of the
acoustic echo canceler.
The gain controller starts controlling when the RIN level is –24 dBm0 or above and has the
control range of 0 to –8.5 dB.
1: Gain control ON
0: Gain control OFF
AECTHR
(HCL)*1
B7
1
B6
—
0
AECCLR
B5
0
AECHD
B4
0
AECCCLP
(NLP)*1
B3
0
1: ON 0: OFF
AECHLD
(ADP)*1
B2
0
AECATT
(ATT)*1
B1
0
MSM7718-01
AECGC
(GC)*1
32/38
B0
0