EM91455 SERIES
TONE/PULSE DIALER WITH LCD INTERFACE
AND I.P.P. DETECT FUNCTION
Operating flow chart
HF
(7)
IPP State
=Hi
(1)
XMUTE
XMUTE=Lo
HKS=Lo
HKS=Lo
HKS=Hi
HF
On-hook State
HF
(2)
(4)
On-hook
Hand-free State
HKS=Lo
Off-hook State
HF
HKS=Hi
(3)
HD
HF
Off-hook
Hand-free State
HD
HF
HD
HF
(6)
On-hook
Hold-line State
(5)
Off-hook
Hold-line State
HD
HD
HKS=Hi
HKS=Lo
<Note> : HF = Handfree
HD = Hold
Truth table
Pin level
Operating state
Input
HKS
H
I/O
XMUTE
H/F
Output
HFO
L
PO
F
F
HDO
L
DTMF
(1) On-hook, idle state
(2) Off-hook line
-
L
H/F
L
L
-
(3) Off-hook, HF line
(4) On-hook, HF line
(5) Off-hook, HD line
(6) On-hook, HD line
(7) IPP state
L
H
L
H
H/F
H/F
L/L
L/L
F
F
F
F
H
H
L
L
L
L
H
H
-
-
-
-
H
L/L
F
H
H
active
Note : F=floating (high impedance); H=logic “High”; L=logic “Low” level.
XMUTE are I/O port, so Input will effect state situation change, and which state dialer stay will
effect output level.
SDO (Serial Data Output) function
The SDO is serial data output which format is same as UART protocol. SDO function is designed to drive LCD
driver and voice synthesizer. So the dialing numbers can be display on LCD screen with EM32100 (or EM32117
). The SDO signal consists of two start bits, six data bits and two stop bits. The bit time is about 3.9 ms (256 Hz)
and output sequences are following by start bits, data bits (LSB to MSB) and stop bits.
1
0
1
bit 0
bit2
data bits
bit3
bit4
bit5
0
bit1
stop bits
start bits
ready
* This specification are subject to be changed without notice.
9.24.1998
8
ELAN [ ELAN MICROELECTRONICS CORP ]
