
2000 May 19
29
Philips Semiconductors
Product specication
One-chip telephone ICs with speech,
dialler and ringer functions
UBA2050(A); UBA2051(A;C)
handbook, full pagewidth
MGM347
TONE DIALLING
PULSE DIALLING
DIALLING
PTS = on
PTS = off
end
dial keys
[*/T] or [P->T]
[R]
+ PTS = on
CONVERSATION
Fig.30 Dialling mode state machine.
Pulse dialling
In this mode all valid keys are dialled by the pulse dialler.
When, during pulse dialling, either [
/T] when MMS is off
or [P
→ T] is pressed, the UBA205xx switches over to
tone dialling (mixed mode dialling). After the switch over,
valid keys are dialled by the tone dialler. The temporary
tone mode is terminated by going on-hook or flash
(Recall).
Tone dialling
The UBA205xx converts valid key entries into data for
the on-chip DTMF generator. Tones are transmitted via
output MDY/TONE with a minimum tone burst/pause
duration. The maximum tone burst duration is equal to
the key pressing time.
Flash function
The [R] key will result in pin DP/FL being set to LOW to
generate a flash (line current interruption) with a
selected time (FTSA and FTSB resistor options).
Pressing one digit after [R] key is pressed clears the
LNR memory. When going on-hook after the [R] key is
pressed, then digits previously dialled in the LNR
memory are kept.
Access pause
When the [LNR/P] button is not the first key pressed, an
access pause is entered for repertory or redialling
procedures.
Last number redial
If the first key pressed is [LNR/P], the number stored in
the LNR memory is dialled and sent. A maximum
number of 32 digits can be stored in the LNR memory.
If this maximum is exceeded the redial function is
inhibited. Pauses, which are stored in the LNR memory,
are also dialled.
The tone switch keys [
/T] (when MMS is off) and
[P
→ T] are also stored in the LNR memory. When a
[
/T] key (when MMS is on) or [#] key occurs during
pulse dialling, its code is not stored in the LNR memory.
The LNR memory is always cleared when the [STORE]
key is pressed. Its content may also be programmed
(see Section “Program state (only UBA2051x)”).