MAX1233_05 Datasheet, PDF (40/45 Pages) Maxim Integrated Products – ±15kV ESD-Protected Touch-Screen Controllers Include DAC and Keypad Controller

±15kV ESD-Protected Touch-Screen
Controllers Include DAC and Keypad Controller
KEY-PRESS-INITIATED DEBOUNCE SCAN
KEYPAD
TOUCH
YES
ARE THERE
UNREAD DEBOUNCE
RESULTS?
NO
SET
KEYIRQ LOW
IS KEYSTS1 = 1?
NO GO TO HOST-INITIATED
DEBOUNCE SCAN
YES
START CLOCK
SET BUSY LOW
SCAN AND DEBOUNCE KEYS
STORE KEYPAD SCAN
RESULTS IN REGISTER
SET BUSY HIGH
RESET KEYIRQ HIGH
DONE
HOST-INITIATED DEBOUNCE SCAN
KEYPAD
TOUCH
YES
ARE THERE
UNREAD DEBOUNCE
RESULTS?
NO
SET
KEYIRQ LOW
IS KEYSTS1 = 1?
YES GO TO KEY-PRESS-INITIATED
DEBOUNCE SCAN
NO
HOST WRITES
ADC
CONTROL REGISTER
START CLOCK
SET BUSY LOW
SCAN AND DEBOUNCE KEYS
STORE KEYPAD SCAN
RESULTS IN REGISTER
SET BUSY HIGH
RESET KEYIRQ HIGH
DONE
Figure 25. Key-Press-Initiated Debounce Scan
Figure 26. Host-Initiated Debounce Scan
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