CHAPTER 14 TOUCH PANEL INTERFACE UNIT (PIU)
User’s Manual U14272EJ3V0UM
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14.6 Timing
14.6.1 Touch/release detection timing
Touch/release detection is not determined via the A/D converter but the voltage level of the TPY1 pin. The
following figure shows a timing of touch/release detection and coordinate detection.
Figure 14-6. Touch/Release Detection Timing
State
Standby
WaitPenTouch
DataScan
Interval
TPY(1:0), TPX(1:0)
(PADSCANTYPE = 0)
Touch detected
Note
Y
−
Release detected
Note
TPY(1:0), TPX(1:0)
(PADSCANTYPE = 1)
Touch detected
Note
X+
Release detected
Note
X
−
Y+
X+
Z
Y
−
Y+
X
−
Note Determined according to the status of the TPY1 signal as follows.
High level … touched
Low level … released
14.6.2 A/D port scan timing
During an A/D port scan, the four ports of A/D converter’s input channel are sequentially scanned and the scanned
data are stored in the data buffers dedicated to A/D port scanning.
The following figure shows an A/D port scan timing diagram.
Figure 14-7. A/D Port Scan Timing
State
XXX
ADPScan
XXX
AUDIOIN,
ADIN(2:0)
ADPSSTART bit
(PIUASCNREG)
ADIN0
ADIN1
ADIN2
AUDIOIN
Remark
XXX: Standby, WaitPenTouch, or Interval