msm7715 Oki Semiconductor, msm7715 Datasheet - Page 13

• Manufacturer Part Number: msm7715
• Description: Multi-function Telecommunication Lsi
• Manufacturer: Oki Semiconductor

¡ Semiconductor
Operation mode selection
By setting the MODE1 to MODE3 pins, an operation mode can be selected (see Table 1). The call
progress tone detector (CPT DET.) can be operated in the DTMF signal transmit mode and
modem mode. However, since the carrier detector is also used for the call progress tone detector,
only rectangular waveform output is available in modem mode. Set CPW = "1" when activating
the call progress tone detector in a modem mode.
* means active.
Note:
DTMF mode setting procedure after power-on or after releasing power-down mode
The following is a recommendable procedure to use DTMF mode after power-on or after
releasing power-down mode.
(1)
(2)
(3)
(4-1)
(4-2)
Modem mode setting procedure after power-on
The following is a recommendable procedure to use Modem mode after power-on.
(1)
(2)
(3)
(4)
(5)
3
0
0
0
0
1
1
1
1
MODE
2
0
0
1
1
0
0
1
1
1
0
1
0
1
0
1
0
1
Put power-on or release power-down mode.
Set DTMF signal transmit mode. PON="0", TEN="1"
Wait more than 20 ms, V
In the case of DTMF receive, set DTMF signal to receive mode.
In the case of DTMF transmit, it is possible control transmit enable (TEN).
Power on.
Set PON="1", TEN="1" and RS="1". Set mode to be used.
More than 200 ms after V
Wait more than 20 ms. V
It is possible to control transmit output. Ignore an output signal from CD and RD of
more than 40 ms which includes the wait time of term (4).
The carrier detecor may malfunction within 40 ms after the operating mode is changed
from the DTMF or power down mode to the modem mode.
Therefore, ignore an output signal from CD and RD during this period of time.
Modem
mode
DTMF mode
operation
Normal
mode
Test
Operation Mode
DTMF signal transmit
DTMF signal receive
Originate (O)
Answer (A)
Analog loopback
(ALB)
Remote digital
loopback (RDLB)
Table 1 Operation Mode Table
DD
DD
DD
becomes more than 2 V, set PON="0".
must be more than 2.5 V after this wait time.
must be more than 2.5 V after this wait time.
O
O
A
A
DTMF
GEN.
*
DTMF
REC.
*
MODEM
Functional Block
FSK
*
*
*
*
*
*
CPW = "1"
*
*
*
*
*
*
*
CPT DET.
CPW = "0"
MSM7715
*
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