Touch Panel Function - Hitachi SH7760 Solution Engine2 Overview

6.4 Touch Panel Functions
This section describes the touch panel functions. In addition, Table 6.4 summarizes the touch panel registers.
For details of each register, refer to 6.4.1 to 6.4.32.
(1) The A/D conversion value of the X or Y position sensed by pen touch is output.
(2) Pen touch ON/OFF interrupt function
• Sampling takes place at intervals of 20msec to 100msec. When the results (A/D conversion value of the X or
Y position) obtained three times from sampling are approximate to each other, a pen touch ON interrupt is
generated for SH7760. In addition, when the touch panel is turned off, a pen touch OFF interrupt is
generated.
(3) To keep the pen touch "ON," sampling is performed at intervals of 20msec to 100msec and a pen touch ON
interrupt is generated if the results obtained from sampling are approximate to each other.
(4) Calibration function
• Calibration is performed when two points on the touch panel are touched with the pen.
• After completion of calibration, the X and Y positions are converted into the LCD drawing dot positions for
output.
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