Datasheet

RL78/L12 CHAPTER 11 A/D CONVERTER
R01UH0330EJ0200 Rev.2.00 340
Dec 13, 2013
11.3.2 A/D converter mode register 0 (ADM0)
This register sets the conversion time for analog input to be A/D converted, and starts/stops conversion.
The ADM0 register can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 11-3. Format of A/D Converter Mode Register 0 (ADM0)
ADCELV0
Note 1
LV1
Note 1
FR0
Note 1
FR1
Note 1
FR2
Note 1
0ADCS
A/D conversion operation control
Stops conversion operation
[When read]
Conversion stopped/standby status
ADCS
0
<0>123456<7>
ADM0
Address: FFF30H After reset: 00H R/W
Symbol
A/D voltage comparator operation control
Note 2
Stops A/D voltage comparator operation
Enables A/D voltage comparator operation
ADCE
0
1
Enables conversion operation
[When read]
While in the software trigger mode: Conversion operation status
While in the hardware trigger wait mode: Stabilization wait status + conversion
operation status
1
Notes 1. For details of the FR2 to FR0, LV1, LV0 bits, and A/D conversion, see Table 11-3 A/D
Conversion Time Selection.
2. In software trigger mode and hardware trigger no-wait mode, the operation of the A/D
voltage comparator is controlled by the ADCS and ADCE bits, and time is required for the
conversion value to stabilize after the A/D converter starts operating (1.0
μ s). Valid
conversion results can therefore be obtained from the first conversion by setting the
ADCE bit to 1 and then waiting for the stabilization time (1.0
μ s) to elapse before setting
the ADCS bit to 1. If the ADCS bit is set to 1 before the stabilization time (1.0 μ s) elapses,
the first conversion data must be ignored.
Cautions 1. Change the FR2 to FR0, LV1, and LV0 bits while conversion is stopped (ADCS =
0, ADCE = 0).
2. Do not set the ADCS bit to 1 and the ADCE bit to 0 at the same time.
3. Do not change the ADCS and ADCE bits from 0 to 1 at the same time by using an
8-bit manipulation instruction. Be sure to set these bits in the order described in
11.7 A/D Converter Setup Flowchart.
4. Be sure to clear bit 6 to 0.