EM91203A EMC [ELAN Microelectronics Corp], EM91203A Datasheet - Page 6

• Manufacturer Part Number: EM91203A
• Description: TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
• Manufacturer: EMC [ELAN Microelectronics Corp]

* This specification are subject to be changed without notice.
Pulse to Tone (*/T or P-T) key operation
The Pulse to Tone (*/T or P-T) key is designed to support toll dialing (long distance call) or PABX system
operation. The "*/T (or P-T)" key can be stored in memory and it will occupy one digital position.
Flash (F) key operation
The Flash (F) key is designed to break telephone line temporarily. After F key is depressed, this dialer will send
a flash signal to break line 600 ms, 300 ms, 100 ms or 80 ms as ROW3 and ROW4 selection.
Handfree (HF) function
The handfree function is designed to support on-hook dialing and loudspeaker application which can be turn “on”
or “off” with falling edge signal from HFI pin. During handfree function is executed, the HFO pin is switched
to “high”. Otherwise the HFO pin stays “low” level.
Truth table
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 EM32116
). The SDO signal consists of two start bits, six data bits and two stop bits. Each 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.
• To select Pulse or Tone mode.
• Off-hook (or turn on HF function), push d1, d2, .. , dn, RD/P, k1, k2, .. , kn . These numbers will be dialed
• To select Pulse mode.
• Off-hook (or turn on HF function), push d1, d2, .. , dn, */T, (or P-T) k1, k2, .. , kn. These numbers will be dialed
out as following sequence:
out as following sequence:
(0) On-hook, idle state
(1) Off-hook line
(2) Off-hook, HF line
(3) On-hook, HF line
Note : F=floating (high impedance); H=logic “High”; L=logic “Low” level.
ready
Operating state
start bits
d1, d2, .. , dn, Tp, k1, k2, .. , kn.
d1, d2, .. , dn, Tpt, k1, k2, .. , kn.
0
(pulse mode)
1
bit 0
HKS
H
H
(tone mode)
L
L
bit1
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
bit2
data bits
PO
F
F
F
F
bit3
Input/Output pin level
XMUTE
bit4
F
F
F
F
bit5
PM
L
L
L
L
0
stop bits
EM91203 SERIES
1
HFO
H
H
L
L
10.1.1997
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