as2574b austriamicrosystems, as2574b Datasheet - Page 5

• Manufacturer Part Number: as2574b
• Description: 20 Number One Touch Dialler With Serial Bus For Display Driver
• Manufacturer: austriamicrosystems

Data Sheet
Recall Function
A recall activation will invoke a flash (timed loop break)
or an earth recall (ER) depending on the ER pin. When
the ER pin is forced to V
ER is open (> 50 k }, an earth recall is executed.
If R is the first entry in a digit string, it will be stored in LNR
RAM.
If the R key is depressed after a digit string has been
dialled out, the recall will not be stored, and subsequently
entered digits will be buffered in the FIFO.
A recall will automatically generate a pause when a recall
is read from a memory and therecall has been stored as
an access code.
A manual invoked earth recall will pull ER high for
minimum 500 ms, but the ER pin is maintained high as
long as the key is depressed.
During auto dial an earth recall is executed with a
duration of 500 ms.
Access Codes
Different access codes (totally up to 18 digit/data inclu-
ding spaces) can be stored in one string. Spaces bet-
ween the different access codes are entered by pressing
the 2nd # during programming. Each access code can
contain up to 4 digits.
digit(s) in a digit string read from the RAM will be
compared with the access code(s) and if equal, a pause
is generated.
Example on programming access codes:
ENTER, 9 , 2nd #, 50
Keep
Release both
The first access code in this example is 9 and the second
50.
Rev. 1
If one or more access codes are stored, the first entered
ENTER
depressed while pressing 0
DD
, a flash is executed; and when
5
Automatic pauses are generated:
- during dialling out from memories when the first digit(s)
- when going Off-hook by pressing LNR, MEM, or M1 -
Any pause can be terminated (shortened) prior to time
out by pressing the LNR key or a high level on the DT
input.
During ACP a pause time out, i.e. DT kept low for > 8
sec., will return the device to idle state.
Pauses are storable as digits within a string of any of the
memories by pressing 2nd # during programming.
Multiple pause entries can be stored up to the maximum
length of the digit string (18 digits/data). A pause is not
accepted in location 1 of a digit string.
If more pauses have been stored in succession, they can
all be terminated by one depression of the LNR key or a
high level on the DT pin for
Sliding Cursor Procedure
To accommodate redialling (LNR) behind a PABX wi-
thout using automatic pause generation (storing access
codes), a sliding cursor protocol is implemented. If new
entries match the previous LNR RAM contents, pressing
the LNR key will dial out the remaining digits.
If there is an error in matching, the LNR will be inhibited
until next On-hook, and the LNR RAM will contain the
new number.
Pause Generation
Pause introduces a delay in signalling digits strings to
accommodate second and subsequent dial tones.
in the digit string equal the stored access code(s)
(pause depends on DT input).
9 (ACP).
1.15 sec.
AS2574B
Jan. 1995