AK4184 Datasheet, PDF (33/36 Pages) Asahi Kasei Microsystems – TSC with Keypad Scanner and GPIO Expander

2. Keypress scan mode
Keypad
Touch
No
Read
KPDATA1,2
Register?
Yes
KEYIRQN pin
Low
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 key press
[AK4184]
MS0603-E-00
33
2007/04