R01UH0822EJ0100 Rev.1.00
Page 843 of 1041
Jul 31, 2019
RX13T Group
26. 12-Bit A/D Converter (S12ADF)
26.3.2.5
A/D Conversion of Internal Reference Voltage
A/D conversion of the internal reference voltage is performed in single scan mode as below.
All channels should be deselected (by setting the ADANSA0 register bits to all 0 and the ADCSR.DBLE bit to 0).
(1) Set the sampling time to 5 μs or longer.
(2) After switching to A/D conversion of the internal reference voltage, start A/D conversion by setting the ADST bit to
1.
(3) When A/D conversion is completed, the conversion result is stored into the A/D internal reference voltage data
register (ADOCDR). If the ADCSR.ADIE bit is 1 (interrupt generation upon scanning completion enabled), a scan
end interrupt request is generated.
(4) The ADST bit remains 1 during A/D conversion, and is automatically cleared to 0 upon completion of A/D
conversion. Then the 12-bit A/D converter enters a wait state.
Figure 26.6
Example of Operation in Single Scan Mode (Internal Reference Voltage Selected)
Auto-discharge
(15 ADCLK cycles)
0Fh
Sampling
(5
s)
A/D
conversion
Interrupt generated
OCSA
ADNDIS[4:0]
ADST
Scan end
interrupt