msm7508b Oki Semiconductor, msm7508b Datasheet - Page 5

• Manufacturer Part Number: msm7508b
• Description: Single Rail Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
MSM7508B/7509B
V
DD
Power supply for +5 V.
PCMIN
PCM signal input.
A serial PCM signal input to this pin is converted to an analog signal in synchronization with the
RSYNC signal and BCLOCK signal.
The data rate of the PCM signal is equal to the frequency of the BCLOCK signal.
The PCM signal is shifted at a falling edge of the BCLOCK 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.
BCLOCK
Shift clock signal input for the PCMIN and PCMOUT signal.
The frequency, equal to the data rate, is 64, 96, 128, 192, 256, 384, 512, 768, 1024, 1536, 1544, or 2048
kHz. 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 required bits are selected from serial PCM signals on the PCMIN pin by the receive
synchronizing signal.
Signals in the receive section are synchronized by this synchronizing signal. This signal must be
synchronized in phase with the BCLOCK. The frequency should be 8 kHz 50 ppm to guarantee
the AC characteristics which are mainly frequency characteristics of the receive section.
However, if the frequency characteristic of an applied system is not specified exactly, this device
can operate in the range of 8 to 10 kHz, but the electrical characteristics in this specification are
not guaranteed. Setting this signal to logic "1" or "0" drives both transmit and receive circuits to
the power saving state.
XSYNC
Transmit synchronizing signal input.
The PCM output signal from the PCMOUT pin is output in synchronization with this transmit
synchronizing signal. This synchronizing signal triggers the PLL and synchronizes all timing
signals of the transmit section.
This synchronizing signal must be synchronized in phase with BCLOCK.
The frequency should be 8 kHz 50 ppm to guarantee the AC characteristics which are mainly
frequency characteristics of the transmit section.
However, if the frequency characteristic of an applied system is not specified exactly, this device
can operate in the range of 8 to 10 kHz, but the electrical characteristics in this specification are
not guaranteed.
Setting this signal to logic "1" or "0" drives both transmit and receive circuits to the power saving
state.
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