MSM7731-02 OKI [OKI electronic componets], MSM7731-02 Datasheet - Page 6

• Manufacturer Part Number: MSM7731-02
• Description: Dual Echo Canceler & Noise Canceler with Dual Codec for Hands-Free
• Manufacturer: OKI [OKI electronic componets]

FEDL7731-02-04
1 Semiconductor
MSM7731-02
SYNC
This is the 8 kHz sync signal I/O pin for digital data communication. This pin is switched to unction as an input or
output by the CLKSEL pin. If the internal clock mode is selected by the CLKSEL pin, an 8 kHz clock
synchronized to be BCLK signal is output and digital data communication is performed. If the external clock mode
is selected by the CLKSEL pin, this pin becomes an input that requires an 8 kHz clock input synchronized to be
BCLK pin, and digital data communication is performed based on this input clock. This pin enables automatic
power-down control. Fixing this pin to a logic “1” or logic “0” causes this device to enter the power-down state.
Two kinds of power-down modes can be selected by the SYPDN (CR11-B0) bit of the control register. For the
power-down mode, refer to the description of control register CR11.
BCLK
This is the shift clock I/O pin for digital data communication. This pin is switched to function as an input or output
by the CLKSEL pin. If the internal clock mode is selected by the CLKSEL pin, a 64 kHz or 128 kHz clock
synchronized to the SYNC signal is output and digital data communication is performed. Switching between 64
kHz and 128 kHz is performed by the PCMSEL pin or PCMSEL (CR11-B1) bit. If -law PCM is selected by the
PCMSEL pin or PCMSEL bit, a 64 kHz clock is output. Or, if 16-bit linear mode is selected, a 128 kHz clock is
output. If the external clock mode is selected by the CLKSEL pin, this pin becomes an input that requires a clock
input synchronized to the SYNC. In this case, the clock frequency range is from 64 kHz to 2048 kHz.
CLKSEL
This pin selects internal or external clock modes for the SYNC and BCLK signals. A logic “0” selects the internal
clock mode. At this time, SYNC and BCLK pins are configured as output pins and each internally generated clock
is output to perform digital data communication. A logic “1” selects the external clock mode and configures the
SYNC and BCLK pins as input pins. At this time, digital data communication is performed with the externally
input SYNC and BCLK clocks. If digital data communication is not used, set this pin to a logic “0” to select
internal clocks. If the pin setting is changed, reset must be activated by either the PDN/RST pin or the PDN/RST
bit (CR0-B7).
PCMI
This is the digital receive signal input pin on the line-side. This input signal is shifted at the rising edge of the
BCLK signal and input. The beginning of digital data is identified on the rising edge of the SYNC signal. The
coding format can be selected as -law PCM or 16-bit linear (2’s complement) by the PCMSEL pin or PCMSEL
(CR11-B1) bit. If the PCMI pin is not used, set it to a logic “1” if -law PCM has been selected, or a logic “0” if
16-bit linear mode has been selected. The sync format can be selected as normal-sync or short-frame-sync by the
SYNCSEL pin. Refer to Figure 3 for the timing. This digital input signal is added internally to the CODEC digital
output signal. Be careful of overflow when using the CODEC.
PCMO
This is the digital transmit signal output pin on the line-side. This output signal is synchronized to the rising edge
of the BCLK and SYNC signals and then output. When not used for output, this pin is in the high impedance state.
It is at high impedance during the power-down reset and the initial modes. The coding format can be selected as
-law PCM or 16-bit linear (2’s complement) by the PCMSEL pin or PCMSEL (CR11-B1) bit. The sync format
can be selected as normal-sync or short-frame-sync by the SYNCSEL pin. Refer to Figure 3 for the timing.
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