msm7617 Oki Semiconductor, msm7617 Datasheet - Page 13

• Manufacturer Part Number: msm7617
• Description: 2-channel Echo Canceler
• Manufacturer: Oki Semiconductor

¡ Semiconductor
PIN DESCRIPTIONS (Continued)
Pin
61
62
63
64
Symbol
SOUT2
ATT2
SIN2
HD2
Type
O
I
I
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.
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.
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.
Because the attenuator is activated opposite the speaker, it is effective for
further reducing echo.
Howling detection control pin for channel 2.
This pin controls detection and canceling of howling generated by the
acoustics of handsfree telephones.
"H": Attenuator off
"L": Attenuator on
"L": Howling detector on
"H": Howling detector off
Description
MSM7617
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