EM91810B EMC [ELAN Microelectronics Corp], EM91810B Datasheet - Page 6

• Manufacturer Part Number: EM91810B
• Description: TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
• Manufacturer: EMC [ELAN Microelectronics Corp]

Handfree function operation:
Operating flow chart of Handfree
SDO (Serial Data Output) function
* This specification are subject to be changed without notice.
A). To execute Handfree function : When HFO = "low", HFI pin is active , the Handfree function will be
enabled (HFO="HIGH").
B). Reset Handfree function:
The SDO is serial data output which format is the same with UART protocol. SDO function is designed to drive
LCD driver and voice synthesizer to display dialing number on LCD screen and announce it to speaker. The SDO
signal consists of two start bits, six data bits and two stop bits.
The frequency of every bit is 256Hz (about 3.9 ms)
There are two categories of dialing data, and representation of serial data is as the following:
(b5,b4=0,0) Digit key
(b5,b4=1,0) Function key
Note : */T key at pulse mode display " "
b3b2b1b0 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110
b3b2b1b0 1010 1111
Display
Display
a. OFF-HOOK action.
b. When HFO="high", a HFI pin is active again , the Handfree function will be reset (HFO="LOW").
Key
Key
(0) INITIAL STATE
(1) ON HKS HF LINE
(2) OFF HKS LINE
(3) OFF HKS HF LINE
HF
1
1
at tone mode display " "
* F : Floating (Hi-impedance)
Start bit
0
2
2
F
F
ON HKS
HF LINE
STATE NO.
HF
1
3
3
(1)
Bit0
4
4
OFF
LSB
Bit1
5
5
ON
PO
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
F
F
F
F
HF
ON HKS
INITIAL
OFF HKS
HF LINE
6
6
Bit2
XMUTE
Data bits
(0)
F
F
F
F
7
7
(3)
HF
OFF
Bit3
8
8
HF
HFO
Bit4
OFF HKS
0
1
0
1
MSB
9
9
(2)
ON
Bit5
0
0
*
* Note :
ON : ON HKS
OFF : OFF HKS
HF : Depress HF key
0
Stop bit
#
1
P
P
10.1.1997
EM91810A/B
P-T
6