AK4184A Datasheet, PDF (32/36 Pages) Asahi Kasei Microsystems – TSC with Keypad Scanner and GPIO Expander

■ Keypad Scanner flowchart
1. ϗετεΩϟϯ
Keypad
Touch
No
Read
KPDATA1,2
Register?
Yes
KEYIRQN pin
Low
Write
KPScanInitiate
Register
Start Clock
BUSY pin
High
Start
Scanning &
Debouncing keys
Store scan results
in KPDATA1, 2
Register
BUSY pin
Low
Stop Clock
KEYIRQN pin
High
Done
Figure 20. Keypad scanner sequence initiated by Host command
[AK4184A]
MS0947-J-00
-32-
2008/04