MSM7617 データシートの表示（PDF） - Oki Electric Industry

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コンポーネント説明

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MSM7617

2-Channel Echo Canceler

Oki Electric Industry 

¡ Semiconductor

MSM7617

PIN DESCRIPTIONS (Continued)

Pin

Symbol Type

Description

61

SIN2

I PCM data input pin. Pin use changes depending on the setting of the IOM

pins (refer to the block diagram). Data is captured on the falling edge of SCK.

In 2-channel parallel I/O mode, this pin becomes SIN for channel 2 and

inputs the PCM signal synchronous with SYNC2. In 2-channel serial I/O

mode, this pin is not used and should be fixed at "L". In 1-channel cross-

connected mode, this pin becomes the cross-connected SIN pin for channel

2, and inputs the PCM signal synchronous with SYNC1.

62

SOUT2

O PCM data output pin. Output signal changes depending on the setting of

the IOM pins (refer to the block diagram).

Data is always output on the rising edge of SCK. This pin becomes high

impedance while there is no data.

In 2-channel parallel I/O mode, this pin becomes SOUT for channel 2 and

outputs the PCM signal synchronous with SYNC2. In other modes, this pin

is not used and should be left open.

63

ATT2

I ATT control pin for channel 2.

This pin controls the ATT function for preventing howling with the

attenuators (ATT) provided on RIN and SOUT. When input is only on RIN,

the SOUT attenuator is activated. When there is no input on SIN or there is

input on both SIN and RIN, the RIN input attenuator is activated. Either the

ATT for the RIN output or the ATT for the SOUT is always activated in all

cases, and the attenuation of ATT is 6 dB.

"H": Attenuator off

"L": Attenuator on

Because the attenuator is activated opposite the speaker, it is effective for

further reducing echo.

64

HD2

I Howling detection control pin for channel 2.

This pin controls detection and canceling of howling generated by the

acoustics of handsfree telephones.

"L": Howling detector on

"H": Howling detector off

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