msm7542 Oki Semiconductor, msm7542 Datasheet - Page 6

• Manufacturer Part Number: msm7542
• Description: Single Rail Codec
• Manufacturer: Oki Semiconductor

¡ Semiconductor
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 the 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 kHz 2 kHz, but the electrical characteristics in this specification are
not guaranteed.
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
the 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 kHz 2 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.
TMC
Control signal input for mode selection.
This pin select the normal operating mode or the analog loop-back mode.
In the analog loop-back mode, the receive filter output is connected to the transmit filter input
and the digital signal input to the PCMIN pin is converted from a digital to an analog signal (D/
A conversion). Next, the analog signal is converted to a digital signal (A/D conversion) through
the receive filter and transmit filter. The result is output to the PCMOUT pin.
When in the analog loop-back mode, the VFRO pin outputs the SG level. (signal ground)
< 0.16 ¥ V
> 0.45 ¥ V
TMC Input
DD
DD
Normal operation
Analog loop-back
Mode
MSM7541/7542
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