RL78/G1P
CHAPTER 9 A/D CONVERTER
R01UH0895EJ0100 Rev.1.00
273
Nov 29, 2019
9.6.3 Software trigger mode (scan mode, sequential conversion mode)
<1> In the stop status, the ADCE bit of A/D converter mode register 0 (ADM0) is set to 1, and the system enters the
A/D conversion standby status.
<2> After the software counts up to the stabilization wait time
Note
, the ADCS bit of the ADM0 register is set to 1 to
perform A/D conversion on the four analog input channels specified by scan 0 to scan 3, which are specified by
the analog input channel specification register (ADS). A/D conversion is performed on the analog input channels
in order, starting with that specified by scan 0.
<3> A/D conversion is sequentially performed on the four analog input channels, the conversion results are stored in
the A/D conversion result register (ADCR, ADCRH) each time conversion ends, and the A/D conversion end
interrupt request signal (INTAD) is generated. After A/D conversion of the four channels ends, the A/D
conversion of the channel following the specified channel automatically starts (until all four channels are finished).
<4> When ADCS is overwritten with 1 during conversion operation, the current A/D conversion is interrupted, and
conversion restarts at the first channel. The partially converted data is discarded.
<5> When the value of the ADS register is rewritten or overwritten during conversion operation, the current A/D
conversion is interrupted, and A/D conversion is performed on the first channel respecified by the ADS register.
The partially converted data is discarded.
<6> Even if a hardware trigger is input during conversion operation, A/D conversion does not start.
<7> When ADCS is cleared to 0 during conversion operation, the current A/D conversion is interrupted, and the
system enters the A/D conversion standby status.
<8> When ADCE is cleared to 0 while in the A/D conversion standby status, the A/D converter enters the stop status.
When ADCE = 0, specifying 1 for ADCS is ignored and A/D conversion does not start.
Note
If a high-accuracy channel is selected as the analog input channel: Stabilization wait time = 0.5
s
If a standard channel is selected as the analog input channel:
Stabilization wait time = 2
s
Figure 9-19. Example of Software Trigger Mode (Scan Mode, Sequential Conversion Mode) Operation Timing
ADCE
ADCS
ADS
INTAD
The interrupt is generated four times.
Data 5
(ANI0)
ANI0 to ANI3
A/D
conversion
status
ADCR,
ADCRH
<1> ADCE is set to 1.
ADCS is set to 1 while in the
conversion standby status.
ADCS is overwritten with
1 during A/D conversion
operation.
A hardware trigger is
generated (and ignored).
ADCS is cleared
to 0 during A/D
conversion operation.
The trigger
is not
acknowledged.
The trigger
is not
acknowledged.
ADS is rewritten during
A/D conversion operation.
ANI4 to ANI7
Conversion is
interrupted and restarts.
Conversion is
interrupted and restarts.
A/D conversion ends and
the next conversion starts.
Stop
status
Conversion
standby
Data 1
(ANI0)
Data 1
(ANI0)
Data 2
(ANI1)
Data 2
(ANI1)
Data 6
(ANI1)
Data 8
(ANI1)
Data 8
(ANI1)
Data 12
(ANI1)
Data 3
(ANI2)
Data 3
(ANI2)
Data 5
(ANI0)
Data 9
(ANI2)
Data 9
(ANI2)
Data 4
(ANI3)
Data 4
(ANI3)
Data 7
(ANI0)
Data 11
(ANI0)
Data 11
(ANI0)
Data 10
(ANI3)
Data 10
(ANI3)
Data 13
(ANI4)
Data 13
(ANI4)
Data 17
(ANI4)
Data 17
(ANI4)
Data 14
(ANI5)
Data 14
(ANI5)
Data 18
(ANI5)
Data 15
(ANI6)
Data 15
(ANI6)
Data 16
(ANI7)
Data 16
(ANI7)
ADCE is cleared to 0. <8>
The interrupt is generated four times.
The interrupt is generated four times.
<2>
<4>
<6>
<7>
<5>
<3>
<3>
<3>
Conversion is
interrupted.
Stop
status
Conversion
standby
Data 7
(ANI0)