LC75857E Datasheet, PDF (12/39 Pages) Sanyo Semicon Device – CMOS IC 1/3, 1/4 Duty LCD Display Drivers with Key Input Function

LC75857E, LC75857W
Control Data Functions
1. SP : Normal mode/sleep mode control data
This control data bit switches the IC between normal mode and sleep mode.
SP Mode
0 Normal
OSC pin state
RC oscillator mode
External clock mode
Oscillator operating
External clock signal accepted
Common and segment
pin output states
LCD drive waveforms
are output
Key scan
operating state
General-purpose
output port states
1 sleep
Oscillator stopped
Acceptance of the external
(The oscillator operates
clock signal is disabled.
during key scan operations.) (The external clock signal is accepted
during key scan operations)
L (VSS)
The state can be set The state can be set
Note: 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.
2. KC0 to KC2 : Key scan output state setting data
These control data bits set the states of the key scan output pins KS1 to KS6.
Control data
Output pin states during key scan standby
KC0
KC1
KC2
KS1
KS2
KS3
KS4
KS5
KS6
0
0
0
H
H
H
H
H
H
0
0
1
L
H
H
H
H
H
0
1
0
L
L
H
H
H
H
0
1
1
L
L
L
H
H
H
1
0
0
L
L
L
L
H
H
1
0
1
L
L
L
L
L
H
1
1
0
L
L
L
L
L
L
Note: 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.
3. KSC : Key scan operation enabled/disabled state setting data
This control data bit enables or disables key scan operation.
KSC
0
1
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.))
4. K0, K1 : Key scan output /segment output selection data
These control data bits switch the functions of the KS1/S40 to KS3/S42 output pins between key scan output and
segment output.
Control data
Output pin state
K0
K1
KS1/S40
KS2/S41
0
0
KS1
KS2
0
1
S40
KS2
1
0
S40
S41
1
1
S40
S41
Note: KSn(n = 1 to 3) : Key scan output
Sn (n = 40 to 42): Segment output
KS3/S42
KS3
KS3
KS3
S42
Maximum number of
input keys
30
25
20
15
No. 7980-12/39