MSM7715 データシートの表示（PDF） - Oki Electric Industry
部品番号
コンポーネント説明
一致するリスト
MSM7715 Datasheet PDF : 21 Pages
| |||
¡ Semiconductor
MSM7715
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.
Table 1 Operation Mode Table
MODE
321
Operation Mode
DTMF
GEN.
000
DTMF signal transmit
*
DTMF mode
001
DTMF signal receive
010
011
Normal Originate (O)
operation Answer (A)
1 0 0 Modem
Analog loopback O
1 0 1 mode Test (ALB)
A
110
mode Remote digital
O
111
loopback (RDLB) A
Functional Block
DTMF FSK
CPT DET.
REC. MODEM CPW = "1" CPW = "0"
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
* means active.
Note: 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.
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)
Put power-on or release power-down mode.
(2)
Set DTMF signal transmit mode. PON="0", TEN="1"
(3)
Wait more than 20 ms, VDD must be more than 2.5 V after this wait time.
(4-1) In the case of DTMF receive, set DTMF signal to receive mode.
(4-2) In the case of DTMF transmit, it is possible control transmit enable (TEN).
Modem mode setting procedure after power-on
The following is a recommendable procedure to use Modem mode after power-on.
(1)
Power on.
(2)
Set PON="1", TEN="1" and RS="1". Set mode to be used.
(3)
More than 200 ms after VDD becomes more than 2 V, set PON="0".
(4)
Wait more than 20 ms. VDD must be more than 2.5 V after this wait time.
(5)
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).
13/21
Share Link: 