as2578 austriamicrosystems, as2578 Datasheet - Page 2

• Manufacturer Part Number: as2578
• Description: Telephone Controller With 13 Memories And 2-wire Bus
• Manufacturer: austriamicrosystems

Data Sheet
Rev. 3
Pin Description
Continues…
Pin #
10
11
13
14
15
12
16
17
1
2
3
4
5
6
7
8
9
Symbol
MODE
TONE
MUTE
MASK
OSC2
OSC1
SDA
SCL
Vss
FCI
MO
HS
CE
C4
C3
C2
C1
Function
Keyboard Columns
Hook Switch Input
This input is active high with internal pull-down resistor.
Signalling (LD/MF) Default Mode Select Input
Chip Enable Input
This input is active high with internal pull-down resistor and is used to initiate setup
procedures.
Oscillator Input
Oscillator Output
Oscillator pins for Xtal or ceramic resonator (3.58 MHz). When a ceramic resonator is used
a capacitor (10 - 22 pF) must be connected from each of the oscillator pins to V
Negative Power Supply
DTMF Tone Output
The dual tones provided at this output have a level independent of the supply voltage in
the operating range from 2.5 to 5.5V.
Serial Data I/O
SDA is a bidirectional pin with an open drain with internal pull-up resistor and is used to
transfer data into and out of a compatible EEPROM.
Serial Clock Line Output
The SCL output is an open drain with internal pull-up resistor and is used to clock data into
and out of a compatible EEPROM.
Frequency Comparator Input
Schmitt trigger input for ring frequency discrimination.
Melody Generator Output
Melodies for tone ringing are generated on this output. The output signal is PDM.
Mute Output
This push-pull output is high during dialling and when mute key has been activated,
otherwise low.
Mask Output
This push-pull output is high during pulsing (make and break periods).
Mode pin
High
Open
Low
Function
LD default mode, make/break pulse 33/66 ms
MF only
LD default mode, make/break pulse 40/60 ms
2
AS2578 /B
March 1997
SS
.