Example: When control data “KP1 and KP2 = 0, KC1 to KC5 = 0, KC6 = 1” are executed.

(i.e.key scanning with only KS6 high.)

No. 7632-11/16

LC75700T

KI3

KI4

KI2

KI1

KI5

*3

[H] KS6

[L] KS5

[L] KS4

[L] KS3

[L] KS2

[L] KS1

When any one of these keys is pressed, the

oscillator on the OSC pin is started and the

keys are scanned.

*3. These diodes are required to reliabled recognize multiple key presses of keys on the KS6 line when state with

only KS6 high, as in the above example. That is, these diodes prevent incorrect operations due to sneak currents

in the KS6 key scan output signal keys on the KS1 to KS5 lines are pressed at the same time.

Key data read request

Key data read

Key data read

DO

DI

Serial data transfer

Key address (63H)

Key address

Serial data transfer

Serial data transfer

CE

Key scan

Key input

(KS6 line)

615T[s]

Key data read request

615T[s]

T=

1

fosc

Multiple Key Presses

Although this LSI is capable of key scanning without inserting diodes for dual key presses, triple key presses on the

KI1 to KI5 input pin lines, or multiple key presses on the KS1 to KS6 output pin lines, multiple presses other than these

cases may result in keys that were not pressed recognized as having been pressed. Therefore, a diode must be inserted

in series with each key.Applications that do not recognize multiple key presses of three or more keys should check the

key data for three or more 1 bits and ignore such data.