bu9768ak ROHM Co. Ltd., bu9768ak Datasheet - Page 14

• Manufacturer Part Number: bu9768ak
• Description: Driver Segmented Module With Input Function
• Manufacturer: ROHM Co. Ltd.

In sleep modes, depending on the mode, the key scan standby state of the KO pin is restricted.
The figure above assumes that the control codes S
any key between key 26 and key 30 is pressed, an HIGH level is input on the KIn line, oscillation begins, and a key
scan is carried out. If any key between key 1 and key 25 is pressed, all of the KIn lines remain at LOW level, and no
key scan is carried out. Oscillation resumes when the key scan has been completed.
If key input in a sleep mode is to be used and interrupt processing carried out, a key on a KOn = HIGH line should be
used.
14
2) Key scans in sleep modes
Standard ICs
(The diodes installed on each key are to prevent erroneous recognition if multiple keys are pressed.)
(L) KO
(H)KO
(L)KO
(L)KO
(L)KO
(L)KO
Standby state in sleep mode
2
3
4
5
6
1
KEY11
KEY16
KEY21
KEY26
KEY1
KEY6
Kl
1
Fig. 11 Example of key matrix configuration
KEY12
KEY17
KEY22
KEY27
KEY2
KEY7
Kl
2
KEY13
KEY18
KEY23
KEY28
KEY3
KEY8
Kl
0
3
and S
1
have been set to 0 and 1, respectively. In this case, if
KEY14
KEY19
KEY24
KEY29
KEY4
KEY9
Kl
4
KEY10
KEY15
KEY20
KEY25
KEY30
KEY5
Kl
BU9768AK / BU9768AKV
5
Key input received
Enlarged view of one key