NEC VR4181 mPD30181 User Manual page 300

64-/32-bit microprocessor hardware
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(3) When transfer of the next coordinate data starts while valid data for both pages remains in the buffer
Cause
This condition is caused when the data buffer contains two pages of valid data (both the data buffer page 1
and data buffer page 0 interrupt requests have occurred) but the valid data has not been processed. If the
A/D converter is used frequently, the time from when both pages become full until when the data loss occurs
may be shorter than that of the normal operation.
Response
In this case, valid data contained in the pages when the data lost interrupt request occurs is never
overwritten.
After two pages of valid data are processed, clear the three interrupt requests by writing 1 to the
PADDLOSTINTR, PADPAGE1INTR, and PADPAGE0INTR bits in the PIUINTREG register.
After clearing these interrupt requests, set the PADATSTART or PADSCANSTART bit of the PIUCNTREG
register to restart the coordinate detection operation.
(4) When the next data transfer starts while there is valid data in the ADPScan buffer
Cause
This condition is caused when valid data is not processed even while the ADPScan buffer holds valid data
(A/D port scan interrupt request occurrence).
Response
In this case, valid data contained in the buffer when the data lost interrupt request occurs is never
overwritten.
After valid data in the buffer is processed, clear the two interrupt requests by writing 1 to the PADDLOSTINTR
and PADADPINTR bits in the PIUINTREG register.
After clearing these interrupt requests, set the ADPSSTART bit of the PIUASCNREG to restart the general-
purpose A/D port scan operation.
300
CHAPTER 14 TOUCH PANEL INTERFACE UNIT (PIU)
User's Manual U14272EJ3V0UM

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