W91570DN SERIES
Publication Release Date: May 1997
- 3 -
Revision A2
PIN DESCRIPTION
SYMBOL
PIN NO.
I/O
FUNCTION
Row,
Column
Inputs
29
−
33
and
20
−
28
I
The keyboard inputs may be used with either the standard 6
×
10
keyboard, an inexpensive single contact (form A) keyboard or
electronic input.
A valid key entry is defined by a single row being connected to
a single column.
XT1,
XT
34, 35
I,
O
A built-in inverter provides oscillation with an inexpensive
3.579545 MHz crystal or ceramic resonater.
The oscillator ceases when a keypad input is not sensed after
chip enable and dialing is finished. The crystal frequency
deviation is
±
0.02%.
T/P
MUTE
16
O
The T/P
MUTE
is a conventional CMOS N-channel open drain
output.
The output transistor is switched on low level during the dialing
sequence (both pulse and tone mode), one-key redial break,
auto redial break and flash break. Otherwise, it is switched off.
H/P MUTE
15
O
The H/P MUTE is a conventional CMOS inverter output. During
pulse dialing, one-key redial break, auto redial break, flash
break, hold, and mercury functions, this pin will output an active
high. It remains in a low state at all other times.
KMUTE
6
O
The
KMUTE
is a CMOS N-channel open drain output. The
output transistor is switched on only during mute function.
Otherwise, it is switched off.
HKS
36
I
Hook switch input.
HKS
= V
DD
or floating: On-hook state. Chip in sleeping mode,
no operation.
HKS
= V
SS
: Off-hook state. Chip enable for normal operation.
HKS
pin is pulled to V
DD
by internal resistor.
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