RL78/F13, F14 CHAPTER 27 SAFETY FUNCTIONS
R01UH0368EJ0210 Rev.2.10 1608
Dec 10, 2015
27.3.10 A/D test function
The A/D test function is used to check whether the A/D converter is operating normally by executing A/D conversions of
an internal voltage of 0 V, the AVREF voltage, and the internal reference voltage (1.45 V).
The below procedure can be used to confirm selection of the analog multiplexer and that wiring is not disconnected.
<1> Perform A/D conversion of the voltage on the ANIx pin (result of conversion 1).
<2> Select AV
REFM with the ADTES register, perform A/D conversion, and set the potential difference between the two
terminals of the sampling capacitor of the A/D converter to 0 V.
<3> Perform A/D conversion of the voltage on the ANIx pin (result of conversion 2).
<4> Select AV
REFP with the ADTES register, perform A/D conversion, and set the potential difference between the two
terminals of the sampling capacitor of the A/D converter to AVREF.
<5> Perform A/D conversion of the voltage on the ANIx pin (result of conversion 3).
<6> Confirm that result of conversion 1 = result of conversion 2 = result of conversion 3.
The above procedure can be used to confirm selection of the analog multiplexer and that wiring is not disconnected.
Remarks 1. When the analog input voltage varies during conversion in steps <1> to <5>, use a different method to
check the analog multiplexer.
2. The result of conversion will include error. Therefore, take the error into consideration when comparing the
results of conversion.
Figure 27-25. Configuration of A/D Test Function
Temperature
sensor
+ side reference
voltage source
(AVREF+)
- side reference
voltage source
(AVREF-)
A/D convertor
ANI0/AVREFP
ANI1/AVREFM
ANIx
ANIx
VDD
V
SS
Internal reference
voltage (1.45 V)
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