SC91215-A SILAN [Silan Microelectronics Joint-stock], SC91215-A Datasheet - Page 9

• Manufacturer Part Number: SC91215-A
• Description: T/P SWITCHABLE DIALER WITH REDIAL HANDFREE FUNCTION
• Manufacturer: SILAN [Silan Microelectronics Joint-stock]

switch the DIALING mode to TONE mode. Unlike NORMAL mode switching, the */T key entry, as the first key
pressed, will not produce any pause time, there are only 31 digits of redial memory available in the buffer to be
used for operation a and b, since the mode switching key, */T, will occupy one digit of space.
PULSE to TONE mode, but not from TONE to PULSE mode. Switching the MODE IN pin to Vss will cause the
chip to store a */T digit prior to first tone digit in the redial memory and will automatically insert a 2.2 second
pause before the tone digits are dialed out. After the mode has been switched, the status of the mode selection
pin will no longer be checked. Therefore, it will not be possible to switch from TONE to PULSE mode.
the mode can be switched to DTMF by pressing the */T key. DTMF mode will being as soon as the last pulse
has been transmitted. In this mode, Dn+1 through Dn+m are sent through the TONE OUT pin as DTMF
signals. If a P key entry is contained in the series of digits before or after the */T entry, or the MODE IN switch
is depressed, 2.2 second pause will be added to the automatically inserted pause time, which is also 3.57
seconds. Both of the above switching modes can store as many as 31 digits in the redial memory.
3. Manual dialing with automatic access pause
4. Redial
disabled while PULSE or TONE signals are being transmitted. Redial will also be inhibited if the last number
dialed exceeds 32 digits because the redial memory can only hold 32 digits.
redial memory will contain the original digits, plus the digits dialed after pressing RD . each time the redial key is
pressed, the stored number will be dialed exactly the same as it was previously, regardless of the status of the
MODE IN pin.
5. TONE/PULSE switch operation
6. One-key redialing
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a. Off Hook D1
The INITIAL mode is PULSE mode if the mode selection pin, MODE IN, is VDD or floating. The */T key can
The mode selection pin is always checked for TONE or PULSE mode key entry. Dialing can be switched from
PULSE mode is initially defined with the mode selection pin, MODE IN, equal to VDD or floating. At this time,
a. Off Hook RD or On Hook
Up to 32 digits (in PULSE mode) or 31 digits (in TONE mode) can be dialed using the RD key. The RD key is
b. Off Hook RD D1
After pressing the RD key, digits may be added to the number in redial memory. When finished dialing, the
Pause key entries can be accepted and stored and stored in the redial memory. Each is stored as a digit.
Each key-in will provide a pause of 3.57 seconds, depending on which model is being used.
a. Off Hook O P
b. Off Hook D1
Off-Hook D1
PULSE Mode
Dn RD or On Hook
Dn MODE IN pin switched to VSS Dn+1
D1
Dn or On Hook
Dn */T Dn+1
PULSE Mode
Dn
HFI
RD
DTMF Mode
HFI
HFI
Dn+m
D1
RD D1
Dn RD
DTMF Mode
Dn
SC91214/91215 SERIES
Dn+m
REV:1.0
Page 9 of 16
2004.08.03