IL91210E Datasheet, PDF (4/11 Pages) Integral Corp. – Tone/Pulse Dialer High-Performance Silicon-Gate CMOS

IL91210E
Operation Procedures
Symbol Definitions:
In the description below, signals are defined in terms of
the key or switch which is activated.
Off Hook ^{means the phone was taken off}
the hook.
On Hook ^{means that the receiver is onf the}
hook.
D1 ^{stands for the first digit dialed in a string}
of digits.
Dn ^{stands for the last digit dialed in a string}
of digits.
Dn+1 ^{stands for the beginning of a new}
string of digits.
Dn+m ^{stands for the last digit in a new string}
of digits.
*/T ^{is the Pulse-to-DTMF key}
RD ^{is the Redial key}
O ^{is the Zero key.}
P ^{is the Pause key.}
F ^{is the Flash key.}
1. Pulse mode operation
a. _{Off Hook D1} . . . . . . _Dn
Pulse mode is defined as the initial mode, provided
the first keyboard input is not the */T key following
the Off Hook condition and the mode selection pin is
V_CC (MODE SELECT = V_CC).
b. Pulse mode is defined as the initial mode, provided
the key input D1 is not */T while the mode selection
pin is V_CC. The chip will pause for 824 ms
automatically after it detects an Off Hook condition.
It then proceeds with pulse or DTMF dialing if any
keys have been depressed. The dialing rate or
make/break ratio is decided at the first key entry by
checking the MODE SELECT & M/B status and will
not be altered. The MODE SELECT status can only
switch the dialing mode from Pulse to DTMF after
the first key entry.
2. DTMF mode operation
a. _{Off Hook D1} . . . . . . _Dn
DTMF mode is defined as the initial mode of the
mode selection pin if MODE SELECT is GND.
b. _{Off Hook */T D1} . . . . . . _Dn
The initial mode is pulse mode if the mode selection
pin, MODE SELECT, is V_CC. The */T key can
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 digit of redial memory
available in the buffer to be used for operations a
and b, since the mode switching key, */T , will
occupy one digit of space.
3. Manual dialing with automatic access pause
Off Hook ^O */T D1 ^{. . . .} Dn
Pause key entries can be accepted and stored in the
redial memory. Each is stored as a digit. Each key-in
will provide a pause of 2.2 seconds, depending on
which model you are using.
4. Redial
a. _{Off Hook RD}
Up to 32 digits (in pulse mode) or 31 digits (in tone
mode) can be dialed using the RD is 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.
b. _{Off Hook RD D1} . . . . . . _Dn
After pressing the RD key, we can add digits to the
number in redial memory. When finished dialing, the
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 SELECT pin.
5. TONE/PULSE switching operation
a. Off Hook D1 . . . Dn
MODE SELECT pin Pulse Mode switched to GND
Dn+1 . . . . Dn+m DTMF Mode
The mode selection pin is always checked for tone or
pulse mode key entry. Dialing can be switched from
pulse to tone mode, but not from tone to pulse mode.
Switching the MODE SELECT pin to GND will
cause the chip to store a */T digit prior to the
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.