AS2534BT Austriamicrosystems, AS2534BT Datasheet - Page 7

• Manufacturer Part Number: AS2534BT
• Description: AS Series 3.8 to 5V Multi-Standard CMOS Telephone IC for Basic Telephone SOIC-28
• Manufacturer: Austriamicrosystems

Data Sheet
The centrex keys are not stored in the RAM, and
subsequently entered digits are buffered in FIFO.
Last Number Redial
LNR is a facility that allows resignalling of the last
manually dialled number without keying in all the digits
again. The LNR is repeatable after each off-hook.
The current content of the RAM is overwritten by new
entries.
A manually entered number is automatically stored in
the LNR RAM. The capacity of the RAM is 31 digits. If a
number greater than 31 digits is entered, the LNR facility
will be inhibited (until new entries < 32 digits) and further
entries will be buffered in FIFO.
Pauses can be inserted by pressing the
AS2535).
Post dialled digits, i.e. digits manually entered after LNR
has been invoked, are not stored in RAM but buffered in
FIFO.
Repeat Dialling (not AS2535)
The last manually dialled number can be repeated
without going on-hook by pressing the RP key. If a
called number is engaged, pressing the RP key will
break the line for 1.6 second (to get a new dial tone) and
after a pause the number will be repeated.
The repeat function is enabled when prior to pressing
the RP key, a number has been dialled, and it can be
invoked an unlimited number of times until next on-hook.
During the 1.6 second break the device is in power down
mode to save current.
Recall Function
A recall (R1, R2 or R3 key) activation will invoke a flash
(timed loop break), however, the R1 flash is never
executed in LD mode. R2 and R3 will be executed
independent of the mode.
If recall is the first entry in a digit string, it will be stored
in LNR RAM when digit(s) are entered after the recall.
If the recall key is depressed after a digit string has been
entered or dialled out, the recall will not be stored but
buffered in the FIFO together with subsequently entered
digit.
If pressing the recall key is not followed by digit entries,
the LNR RAM remains intact.
After a recall a 270 ms pause will automatically be
executed.
Rev. 7
PS
key (not
7
Memory Keys (not AS2534)
The keys
the
dialling.
Memory arrangement AS2533/6 AS2534 AS2535
Storable numbers
Direct memory keys
Indirect memories
In the on chip RAM, numbers can be stored. Each
number can contain up to 21 digits (including pauses).
During programming multiple pauses can be inserted by
pressing the
pause inserted within the first 5 entries will automatically
be terminated after 2 seconds whereas pauses inserted
after location 5 in a digit string will halt dialling and can
be terminated manually by pressing the
or the
extention on a PABX.
Example (45678–123 is stored in M1, where – is a
pause/wait and 123 the extention number):
Memory dialling is cascadable. However, the content of
one memory must be dialled out before a new can be
invoked.
Sliding Cursor Procedure
To accommodate easy and uncomplicated redialling
(LNR) behind a PABX, a sliding cursor protocol is
implemented. If new entries match the previous RAM
contents, pressing the
digits.
If there is an error in matching, the LNR will be inhibited
until next on-hook, and the RAM will contain the new
number.
Example (LNR content 912345, where 9 is access
code):
Tone Generator
The tone generator incorporates the DTMF tones, 3
basic frequencies for the tone ringer and pacifier tones.
MR
LNR
off-hook, wait for dial tone
press M1 (45678 is dialled out)
await dial tone from called PABX
press PS or LNR (123 is dialled out).
off-hook, wait for PABX dial tone
press 9 and wait for external dial tone
press LNR (12345 will be dialled out).
key (AS2533/6 only) is used for abbreviated
M1
key. The halt function allows in-dialling to an
to
PS
M12
(not AS2535) or the
are direct memory access keys and
LNR
key will dial out the remaining
14
10
4
0
0
0
PS
AS2533...6
LNR
(not AS2535)
key. Each
July 1998
12
12
0