RL78/G1P
CHAPTER 9 A/D CONVERTER
R01UH0895EJ0100 Rev.1.00
287
Nov 29, 2019
9.7.4 Setup when temperature sensor output voltage/internal reference voltage is selected (example for software
trigger mode and one-shot conversion mode)
Figure 9-32. Setup when temperature sensor output voltage/internal reference voltage is selected
The ADCEN bit of the PER0 register is set (1), and supplying the clock
starts.
• ADM0 register
FR2 to FR0, and LV0 bits: These are used to specify the A/D conversion time.
ADMD bit: This is used to specify the select mode.
• ADM1 register
ADTMD1 and ADTMD0 bits: These are used to specify the software trigger mode.
ADSCM bit: One-shot conversion mode
• ADM2 register
ADREFP1, ADREFP0, and ADREFM bits: These are used to select the reference
voltage source.
ADRCK bit: This is used to select the range for the A/D conversion result comparison
value generated by the interrupt signal from AREA1, AREA3, and
AREA2.
ADTYP bit: 8-bit/12-bit resolution
• ADUL/ADLL register
These are used to specify the upper limit and lower limit A/D conversion result
comparison values.
• ADS register
ADISS, ADS4, and ADS2 to ADS0 bits: These are used to select temperature sensor
output voltage or internal reference voltage.
Start of setup
PER0 register setting
• ADM0 register setting
• ADM1 register setting
• ADM2 register setting
• ADUL/ADLL register setting
• ADS register setting
ADCE bit setting
Reference voltage stabilization
wait time count B
Start of A/D conversion
ADCS bit setting
ADCS bit setting
End of A/D conversion
The ADCE bit of the ADM0 register is set (1), and the system enters the
A/D conversion standby status.
If a temperature sensor output voltage or internal reference output
(ADISS bit of ADS register = 1) is selected as the analog input channel: B = 2 µs
The A/D conversion end interrupt (INTAD) will be generated.
After ADISS is set (1), the initial conversion result cannot be used.
The ADCS bit of the ADM0 register is set (1), and A/D conversion starts.
The conversion results are stored in the ADCR and ADCRH registers.
Start of A/D conversion
The A/D conversion end interrupt (INTAD) is generated.
Note
Storage of conversion results in
the ADCR and ADCRH
registers
End of A/D conversion
After counting up to the reference voltage stabilization wait time count B ends, the
ADCS bit of the ADM0 register is set (1), and A/D conversion starts
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Reference voltage stabilization
wait time count A
The reference voltage stabilization wait time count A is required when the value of
the ADREFP1 and ADREFP0 bits is changed.
If change the ADREFP1 and ADREFP0 = 0, 0 or 0, 1: A = 1 µs
If change the ADREFP1 and ADREFP0 = 1, 0: Setting prohibited
Note
Depending on the settings of the ADRCK bit and ADUL/ADLL register, there is a possibility of no interrupt signal
being generated. In this case, the results are not stored in the ADCR and ADCRH registers.
Caution This setting can be used only in HS (high-speed main) mode. For detail, refer to Figure 22-3 Format
of User Option Byte (000C2H).