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CHAPTER 13 8/10-BIT A/D CONVERTER
13.7 A/D Converted Data Preservation Function
The converted data preservation function is executed when A/D conversion is
performed while interrupts are enabled.
I A/D converted data preservation function
This A/D converter has only one data register for storing converted data. When A/D conversion
is performed, data stored in the data register is stored externally and rewritten at the end of
conversion. Therefore, if the converted data is not fully transferred to memory before the
converted data in the data register is rewritten, some of the data is lost. To cope with this
problem, the data preservation function is executed when interrupts are enabled (INTE = 1) as
described below.
When converted data is stored in the A/D data register (ADCR), the INT bit of A/D control status
register 1 (ADCS1) is set to 1. While this bit is 1, A/D conversion temporarily stops. When the
INT bit is cleared after the data in the A/D data register (ADCR) is transferred to memory within
the interrupt routine, the temporary stop is released.
Notes:
•
The converted data preservation function operates only when interrupts are enabled
(ADCS1: INTE = 1).
•
Restarting the converter while it is temporarily stopped might lead to corruption of the data
on standby.
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