¡ Semiconductor

MSM7705-01/02/03

5/20

DIN1, DIN2, DIN3

PCM signal inputs for channels 1, 2, and 3 when the parallel mode is selected.

D/A conversion is performed by the serial PCM signals to these pins, the RSYNC signals

synchronous with the serial PCM signals, and the BCLK signal. Then the analog signals are

output from AOUT1, AOUT2, and AOUT3 pins, respectively.

The data rate of the PCM signal is equal to the frequency of the BCLK signal.

The PCM signal is shifted at the falling edge of the BCLK signal and latched into the internal

register when shifted by eight bits.

The start of the PCM data (MSD) is identified at the rising edge of RSYNC.

When the serial mode is selected, this pin is not used and should be connected to GND (0 V).

DIN4

PCM signal input for channel 4 when the parallel mode is selected.

D/A conversion is performed by the serial PCM signal to this pin, the RSYNC signal synchronous

with the serial PCM signal, and the BCLK signal. Then the analog signal is output from AOUT4

pin.

The data rate of the PCM signal is equal to the frequency of the BCLK signal.

The PCM signal is shifted at the falling edge of the BCLK signal and latched into the internal

register when shifted by eight bits.

The start of the PCM data (MSD) is identified at the rising edge of RSYNC.

When the serial mode is selected, this pin is used for the 4ch multiplexed PCM signal input.

BCLK

Shift clock signal input for DIN1, DIN2, DIN3, DIN4, DOUT1, DOUT2, DOUT3, and DOUT4.

The frequency is equal to the data rate. Setting this signal to logic "1" or "0" drives both transmit

and receive circuits to the power saving state.

RSYNC

Receive synchronizing signal input.

Eight bits of PCM data required are selected from a series of PCM signal to the DIN1, DIN2, DIN3,

and DIN4 pins by the receive synchronizing signal.

All timing signals in the receive section are synchronized by this synchronizing signal. This

signal must be synchronized in phase with the BCLK (generated from the same clock source as

BCLK). The frequency should be 8 kHz

±50 ppm to guarantee the AC characteristics which are

mainly the frequency characteristics of the receive section.

However, this device operates in the range of 6 kHz to 10 kHz unless the frequency characteristics

of the system used are strictly specified, but the electrical characteristics specified in the data

sheet are not guaranteed.