msm7540 Oki Semiconductor, msm7540 Datasheet - Page 6

• Manufacturer Part Number: msm7540
• Description: Single Rail Adpcm Codec
• Manufacturer: Oki Semiconductor

FEDL7540-03
MSM7540/7560
¡ Semiconductor
PCMSI
Transmit PCM data input.
This signal is converted to the transmit ADPCM data. PCM is shifted in synchronization with
the falling edge of BCLKB. Normally, this pin is connected to PCMSO.
PCMRO
Receive PCM data output.
PCM is the output signal after ADPCM decoder processing. This signal is output serially from
MSB in synchronization with the rising edge of BCLKB and RSYNC.
PCMRI
Receive PCM data input.
PCM is shifted on the falling edge of the BCLKB and input from MSB. Normally, this pin is
connected to PCMRO.
IS
Transmit ADPCM signal output.
After having encoded PCM with ADPCM, this signal is output from MSB in synchronization
with the rising edge of BCLKA and XSYNC . This pin is an open drain output and remains in a
high impedance state during power-down. IS requires a pull-up resistor.
IR
Receive ADPCM signal input.
The ADPCM signal is shifted in series and synchronization with the falling edge of BCLKA and
RSYNC, starting with MSB.
BCLKB
Shift clock input for the PCM data (PCMSO, PCMSI, PCMRO, PCMRI).
The frequency is set in the 64 kHz to 2048 kHz range.
XSYNC
8 kHz synchronous signal input for transmit PCM and ADPCM data.
Synchronize this signal with BCLKA and BCLKB signal. XSYNC is used to indicate the MSB of
the serial PCM and ADPCM data stream.
Be sure to input the XSYNC signal because it is also used as the input of the timing generator.
RSYNC
8 kHz synchronous signal input for receive PCM and ADPCM data.
Synchronize this signal with BCLKA and BCLKB signal. RSYNC is used to indicate the MSB of
the serial PCM and ADPCM data stream.
BCLKA
Shift clock input for the ADPCM data (IS, IR).
The frequency is set in the range of 32 kHz to 2048 kHz.
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