msm7719-01 Oki Semiconductor, msm7719-01 Datasheet - Page 11

• Manufacturer Part Number: msm7719-01
• Description: Echo Canceler With Adpcm Transcoder
• Manufacturer: Oki Semiconductor

MSM7719-01
¡ Semiconductor
ECMODE
This pin specifies the operating mode of the echo canceler. When set to logic “0”, this device
operates as a line echo canceler (with cancelable echo delay time of 27 ms max.) + an acoustic echo
canceler (with cancelabel echo delay time of 27 ms max.); when set to logic “1”, it operates as a line
echo canceler (with cancelable echo delay time of 54 ms max.).
When this pin control is not used (i.e., when controlling by the control register), set these pins
to logic “0”.
LTHR, ATHR
(L: Line A: Acoustic)
These pins control the through mode of the echo canceler. In this mode, SinL/A data and RinL/A
data is output directly to SoutL/A and RoutL/A respectively, while retaining their echo canceler
coefficients.
0: Normal mode (Echo cancellation) 1: Through mode
When this pin control is not used (i.e., when controlling by the control register), set these pins to logic
“1”.
LDCL, ADCL
These pins control clearing the coefficient 1 of the adaptive FIR filter used by the echo canceler. If
the echo path changes, reset both the coefficient 1 (by setting LDCL/ADCL to “0”) and the coefficient
2 (by setting LCCL/ACCL to “0”) of the adaptive FIR filter whenever possible.
0: Resets the coefficient 1: Normal operation
When this pin control is not used (i.e., when controlling by the control register), set these pins to logic
“1”.
LCCL, ACCL
These pins control clearing the coefficient 2 of the adaptive FIR filter used by the echo canceler. If
the echo path changes, reset both the coefficient 1 (by setting LDCL/ADCL to “0”) and the coefficient
2 (by setting LCCL/ACCL to “0”) of the adaptive FIR filter whenever possible.
0: Resets the coefficient 1: Normal operation
When this pin control is not used (i.e., when controlling by the control register), set these pins to logic
“1”.
LHD, AHD
Howling detection ON/OFF control pins.
0: OFF, 1: ON
When this pin control is not used (i.e., when controlling by the control register), set these pins to logic
“0”.
LCLP, ACLP
These pins turn ON or OFF the Center Clipping funciton that forcibly sets the SoutL output of the
line echo canceler to minimum positive value when it is –57 dBm0 or less.
0: Center Clipping OFF
1: Center Clipping ON
When this pin control is not used (i.e., when controlling by the control register), set these pins to logic
“0”.
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