lc75857e Sanyo Semiconductor Corporation, lc75857e Datasheet - Page 12

• Manufacturer Part Number: lc75857e
• Description: 1/3, 1/4 Duty Lcd Display Drivers With Key Input Function
• Manufacturer: Sanyo Semiconductor Corporation

Control Data Functions
1. SP : Normal mode/sleep mode control data
Note:
2. KC0 to KC2 : Key scan output state setting data
Note:
3. KSC : Key scan operation enabled/disabled state setting data
4. K0, K1 : Key scan output /segment output selection data
Note: KSn(n = 1 to 3) : Key scan output
SP
0
1
KC0
K0
This control data bit switches the IC between normal mode and sleep mode.
These control data bits set the states of the key scan output pins KS1 to KS6.
This control data bit enables or disables key scan operation.
These control data bits switch the functions of the KS1/S40 to KS3/S42 output pins between key scan output and
segment output.
0
0
0
0
1
1
1
Control data
0
0
1
1
KSC
Sn (n = 40 to 42): Segment output
Normal
0
1
Mode
sleep
See the descriptions of the KC- to KC2, KSC, K0, K1, and P0 to P2 bits in the control data for details on setting the key scan operating state and
setting the general-purpose output port state.
This assumes that the KS1/S40 to KS3/S42 output pins are selected for key scan output.
Also note that key scan output signals are not output from output pins that are set to the low level.
Control data
KC1
K1
0
0
1
1
0
0
1
0
1
0
1
during key scan operations.) (The external clock signal is accepted
(The oscillator operates
Key scan operating state
Key scan operation enabled
(A key scan operation is performed if any key on the lines corresponding to KS1 to KS6 pin which is set high is pressed .)
Key scan operation disabled
(No key scan operation is performed, even if any of the keys in the key matrix are pressed. If this state is set up, the key data
is forcibly reset to 0 and the key data read request is also cleared. (DO is set high.))
Oscillator operating
RC oscillator mode
Oscillator stopped
KC2
KS1/S40
0
1
0
1
0
1
0
KS1
S40
S40
S40
KS1
H
L
L
L
L
L
L
Output pin state
OSC pin state
KS2/S41
Output pin states during key scan standby
KS2
KS2
S41
S41
KS2
H
H
L
L
L
L
L
External clock signal accepted
during key scan operations)
Acceptance of the external
clock signal is disabled.
External clock mode
KS3
H
H
H
L
L
L
L
KS3/S42
LC75857E, LC75857W
KS3
KS3
KS3
S42
KS4
H
H
H
H
L
L
L
Maximum number of
KS5
H
H
H
H
H
L
L
input keys
30
25
20
15
Common and segment
LCD drive waveforms
KS6
pin output states
H
H
H
H
H
H
L
are output
L (VSS)
The state can be set The state can be set
operating state
Key scan
output port states
General-purpose
No. 7980-12/39