RL78/G1P
CHAPTER 9 A/D CONVERTER
R01UH0895EJ0100 Rev.1.00
284
Nov 29, 2019
9.7.1 Setting up software trigger mode
Figure 9-29. Setting up Software Trigger Mode
Start of setup
PER0 register setting
ADPC and PMC1 register settings
PM register setting
The ADCEN bit of the PER0 register is set (1), and supplying the clock starts.
The ports are set to analog input.
ANI0 to ANI7 pins: Set using the ADPC register
ANI16 pin: Set using the PMC1 register
The ports are set to the input mode.
ADM0 register
FR2 to FR0, and LV0 bits:
These are used to specify the A/D conversion time.
ADMD bit: Select mode/scan mode
ADM1 register
ADTMD1 and ADTMD0 bits: These are used to specify the software trigger mode.
ADSCM bit: Sequential conversion mode/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
ADS4, ADS2 to ADS0 bits: These are used to select the analog input channels.
ADCE bit setting
The ADCE bit of the ADM0 register is set (1), and the system enters the A/D conversion
standby status.
Reference voltage stabilization
wait time count B
If a high-accuracy channel is selected as the analog input channel: B = 0.5
s
If a standard channel is selected as the analog input channel: B = 2
s
Start of A/D conversion
End of A/D conversion
The A/D conversion operations are performed.
The A/D conversion end interrupt (INTAD) is generated.
Note
Storage of conversion results in
the ADCR and ADCRH registers
The conversion results are stored in the ADCR and ADCRH registers.
ADCS bit setting
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.
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 = 1, 0:
A = 10
s
If change the ADREFP1 and ADREFP0 = 0, 0 or 0, 1: A = 1
s
ADM0 register setting
ADM1 register setting
ADM2 register setting
ADUL/ADLL register setting
ADS register setting
(The order of the settings is
irrelevant.)
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.