msm7719-01 Oki Semiconductor, msm7719-01 Datasheet - Page 25

• Manufacturer Part Number: msm7719-01
• Description: Echo Canceler With Adpcm Transcoder
• Manufacturer: Oki Semiconductor

¡ Semiconductor
(1)CR0 (Basic operating mode settings)
* :
B7 … Not used
B6 … Power-down (entire system)
B5 … Power-down reset (entire system)0: Power-on 1: Power-down reset
B4 … Not used
B3, 2, 1, 0 … Selection of an operating mode
CR0
Initial value *
ORed with the inverted external power-down signals
Set the PDWN pin to “1” when this register is used. The control registers and their internal
variables are retained.
ORed with the inverted external power-down reset signals
Set the PDN/RST pin to “1” when this register is used. The control registers and their internal
variables are reset.
(0, 0, 0, 0) : Initial mode
This mode enables a change (see Fig. 5) in memory that contains internal default values such
as tone generation frequencies.
In this mode, the PCM output pin acts to output idle patterns and the PCM input pin acts to
input idle patterns; the echo canceler and the ADPCM transcoder do not operate. When
power-down reset occurs or when power-down is released, the device enters the initial mode
about 200 ms after that. When the MCUSL pin is set to “1”, this mode is skipped. This mode
is released by setting any of the following modes:
(0, 1, 0, 0) : Handsfree conversation mode
The tone detector, the ADPCM encoder/decoder, the tone generator, the line echo canceler,
and the acoustic echo canceler become operative and can be controlled by the contents of the
control registers.
(0, 1, 0, 1) : Line echo canceler expansion mode
The tone detector, the ADPCM encoder/decoder, the tone generator, and the line echo
canceler (54 ms) become operative and can be controlled according to the contents of the
control registers.
(Others): Not used
This register is internally processed by a logical OR of the MCUSL pin and B2, and
between the ECMODE pin and B0.
Indicates the value to be set when a resetting is made through the PDN/RST pin. (Also when
reset by bit 5 (B5, PDN/RST), the other bits of CR0 are reset to initial values.)
B7
—
0
PDWN
B6
0
PDN/RST
B5
0
0: Power-on 1: Power-down
B4
—
0
MODE3
OPE
B3
0
MODE2
OPE
B2
0
MODE1
OPE
B1
0
MSM7719-01
MODE0
OPE
25/40
B0
0