MSM7731-01 데이터 시트보기 (PDF) - Oki Electric Industry

부품명

상세내역

제조사

MSM7731-01

Multifunction PCM CODEC (Voice Signal Processor)

Oki Electric Industry 

¡ Semiconductor

MSM7731-01

LGC/AGC

This pin turns ON or OFF the gain control function to control the input level and prevent

howling by means of gain controls (GainL/A) provided in the RinL/A inputs of the 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. A logic "0" turns the function ON and a logic "1" turns the

function OFF. Since this pin is ORed with the CR4-B0 and CR5-B0 bits of the control register,

set the pin to a logic "0" when controlling by the control register. Because data is shifted into this

pin in synchronization with the rising edge of the SYNC signal, hold the data at the pin for 250

ms or longer. For further details, refer to the electrical characteristics.

Notes:

Lxx/Axx: In the above, Lxx refers to line echo canceler control pins and Axx to acoustic echo

canceler control pins.

xxL/xxA: In the above pin descriptions, xxL refers to line echo canceler functions and xxA to

acoustic echo canceler functions.

GLPADTHR

This is the mode control pin for the attenuators (LPADL/A) provided in the SinL/A inputs and

the amplifiers (GPADL/A) provided in the SoutL/A outputs of the echo canceler. A logic "0"

selects the "through mode" and a logic "1" selects the normal mode (PAD operation). The levels

are set by the CR10 register. Settings of ±18, ±12, ±6 and 0 dB are possible. The default setting

is ±12 dB. If the echo return loss (value of returned echo) is amplified, set the LPAD level such

that echo return loss will be attenuated. It is recommended to set the GPAD level to the positive

level equal to the LPAD level. Since this pin is ORed with the CR1-B2 bit of the control register,

set the pin to a logic "0" when controlling by the control register. Because data is shifted into this

pin in synchronization with the rising edge of the SYNC signal, hold the data at the pin for 250

ms or longer. For further details, refer to the electrical characteristics.

NCTHR

This is the noise canceler "through mode" control pin. In the "through mode" the noise canceler

is halted and data is directly output. A logic "0" selects the normal mode (noise canceler

operation) and a logic "1" selects the "through mode". Since this pin is ORed with the CR1-B0

bit of the control register, set the pin to a logic "0" when controlling by the control register.

Because data is shifted into this pin in synchronization with the rising edge of the SYNC signal,

hold the data at the pin for 250 ms or longer. For further details, refer to the electrical

characteristics. When this pin is changed from normal mode to "through mode", approximately

20 ms of data dropout will occur.

SLPTHR

This is the "through mode" control pin for the transmit slope filter. In the "through mode", the

filter is halted and data is directly output. A logic "0" selects the normal mode (slope filter

operation) and a logic "1" selects the "through mode". Since this pin is ORed with the CR1-B1

bit of the control register, set the pin to a logic "0" when controlling by the control register.

Because data is shifted into this pin in synchronization with the rising edge of the SYNC signal,

hold the data at the pin for 250 ms or longer. For further details, refer to the electrical

characteristics.

11/43

Share Link: