NT91214 Datasheet, PDF (8/23 Pages) List of Unclassifed Manufacturers – Tone/Pulse Dialer

NT91214/15 Series
Pin Descriptions (continued)
Pin No.
NT91215A NT91215B NT91215C NT91215D ^{Designation I/O}
NT91214A NT91214B NT91214C NT91214D
Description
1
1
HFO
O Hands-Free Control I/O pins
These pins enable and disable the Hands-
Free control function. When input pin HFI
goes low, the Hands-Free Control state is
toggled on. The status of the Hands-Free
control state is listed in the following table:
(N.A.)
(N.A.)
18
20
Current
State
Next State
Hook
sw.
HFO
Input
HFO
Dialing?
- Low _HFI High Yes
↓
HFI
I
On
Hook ^{High HFI}
Low
No
↓
Off
Hook
High _HFI
Low
Yes
↓
On
Hook
-
Off
Hook
Low
Yes
Off
On
Hook ^Low Hook ^Low
No
Off
Hook
High
On
Hook
High
Yes
7
7
8
8
TONE
O Tone dialing output
When a valid keypress is detected in the
DTMF mode, appropriate low group and
high group, frequencies are generated
which hybridizes the dual tone output.
TONE output is in the "OFF" state in
PULSE mode.
8
V1.0