LC75857E Datasheet, PDF (17/39 Pages) Sanyo Semicon Device – CMOS IC 1/3, 1/4 Duty LCD Display Drivers with Key Input Function

LC75857E, LC75857W
Output Data
1. KD1 to KD30 : Key data
When a key matrix of up to 30 keys is formed from the KS1 to KS6 output pins and the KI1 to KI5 input pins and
one of those keys is pressed, the key output data corresponding to that key will be set to 1. The table shows the
relationship between those pins and the key data bits.
KS1/S40
KS2/S41
KS3/S42
KS4
KS5
KS6
KI1
KD1
KD6
KD11
KD16
KD21
KD26
KI2
KD2
KD7
KD12
KD17
KD22
KD27
KI3
KD3
KD8
KD13
KD18
KD23
KD28
KI4
KD4
KD9
KD14
KD19
KD24
KD29
KI5
KD5
KD10
KD15
KD20
KD25
KD30
When the KS1/S40 and KS2/S41 output pins are selected to be segment outputs by control data bits K0 and K1 and a
key matrix of up to 20 keys is formed using the KS3/S42,KS4 to KS6 output pins and the KI1 to KI5 input pins, the
KD1 to KD10 key data bits will be set to 0.
2. SA : Sleep acknowledge data
This output data bit is set to the state when the key was pressed. Also, while DO will be low in this case, if serial data
is input and the mode is set (to normal or sleep mode) during this period, that mode will be set. SA will be 1 in sleep
mode and 0 in normal mode.
Sleep Mode Functions
Sleep mode is set up by setting SP in the control data to 1. When sleep mode is set up, both the segment and the common
outputs will go to the low level. In RC oscillator mode (OC = 0), the oscillator on the OSC pin will stop (although it will
operate during key scan operations), and in external clock mode (OC = 1), the external clock signal reception on the OSC
pin will stop (although the clock signal will be received during key scan operations). Thus this mode reduces power
consumption. However, the S1/P1 to S4/P4 output pins can be used as general-purpose output ports under control of the
P0 to P2 bits in the control data even in sleep mode. Sleep mode is cancelled by setting SP in the control data to 0.
No. 7980-17/39