R01UH0823EJ0100 Rev.1.00
Page 1587 of 1823
Jul 31, 2019
RX23W Group
44. 12-Bit A/D Converter (S12ADE)
44.3.2.3
A/D Conversion of Temperature Sensor Output/Internal Reference Voltage
A/D conversion of the temperature sensor output and internal reference voltage is performed in single scan mode as
below.
All channels should be deselected (by setting the ADANSA0 and ADANSA01 register bits to all 0 and the
ADCSR.DBLE bit to 0). When selecting A/D conversion of the temperature sensor output, the A/D conversion select bit
for the internal reference voltage (ADEXICR.OCSA) should be set to 0 (deselected). When selecting A/D conversion of
the internal reference voltage, the A/D conversion select bit for the temperature sensor output (ADEXICR.TSSA) should
be set to 0 (deselected).
(1) Set the sampling time to 5 μs or longer.
(2) After switching to A/D conversion of the internal reference voltage or the temperature sensor output, 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 corresponding A/D temperature sensor
data register (ADTSDR) or A/D internal reference voltage data register (ADOCDR). If the ADCSR.ADIE bit is 1
(S12ADI0 interrupt upon scanning completion enabled), an S12ADI0 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 44.7
Example of Operation in Single Scan Mode (Temperature Sensor Output or Internal Reference
Voltage Selected)
Auto-discharge
(15 ADCLK cycles)
0Fh
Sampling
(5
s)
A/D
conversion
Interrupt generated
TSSA/OCSA
ADNDIS[4:0]
ADST
S12ADI0