MAX1233_05 Datasheet, PDF (39/45 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
SCREEN
TOUCH
HOST-INITIATED
X-, Y-, AND Z- SCREEN SCAN
TURN ON DRIVERS: Y+, X-
YES
ARE THERE
UNREAD SCAN
RESULTS?
TURN ON DRIVERS: X+, X-
NO
SET
PENIRQ LOW
IS PENSTS
BIT = 1?
NO
YES
GO TO
TOUCH-INITIATED
SCAN
(FIGURE 22)
HOST WRITES
ADC
CONTROL REGISTER
NO IS TOUCH-SCREEN
SETTLING DONE?
YES
POWER UP ADC
CONVERT Y- COORDINATES
START CLOCK
SET BUSY LOW
TURN ON DRIVERS: Y+, Y-
NO
IS DATA
AVERAGING DONE?
YES
STORE Y- COORDINATES IN
Y- REGISTER
NO IS TOUCH-SCREEN
SETTLING DONE?
YES
POWER UP ADC
POWER DOWN ADC
NO IS TOUCH-SCREEN
SETTLING DONE?
YES
POWER UP ADC
CONVERT Z1- COORDINATES
NO
IS DATA
AVERAGING DONE?
YES
STORE Z1- COORDINATES
IN Z1- REGISTER
CONVERT Z2- COORDINATES
NO
IS DATA
AVERAGING DONE?
YES
STORE Z2- COORDINATES
IIN Z2- REGISTER
POWER DOWN ADC
CONVERT X- COORDINATES
SET BUSY HIGH
NO
IS DATA
AVERAGING DONE?
YES
STORE X- COORDINATES
IN X- REGISTER
POWER DOWN ADC
TURN OFF CLOCK
RESET PENIRQ HIGH
DONE
Figure 24. Host-Initiated X-, Y-, and Z- Coordinate Screen Scan
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