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RL78/G1A CHAPTER 11 A/D CONVERTER
R01UH0305EJ0200 Rev.2.00 340
Jul 04, 2013
CHAPTER 11 A/D CONVERTER
The number of analog input channels of the A/D converter differs, depending on the product.
25-pin 32-pin 48-pin 64-pin
Total
13 ch 18 ch 24 ch 28 ch
High accuracy
channel
Pins based
on input
buffer power
supply
AVDD
4 ch
(ANI0 to ANI3)
5 ch
(ANI0 to ANI4)
9 ch
(ANI0 to ANI8)
13 ch
(ANI0 to ANI12)
Pins based
on input
buffer power
supply V
DD
9 ch
(ANI16 to ANI18, ANI20,
ANI21, ANI25 to ANI27,
ANI29)
13 ch
(ANI16 to ANI24,
ANI26 to ANI29)
15 ch
(ANI16 to ANI30)
−
Analog
input
channels
Standard
channel
Pins based
on input
buffer power
supply EV
DD0
− − − 15 ch
(ANI16 to ANI30)
Remark Most of the following descriptions in this chapter use the 64-pin products as an example. With 25 to 48-pin
products, replace EV
DD0 with VDD, or replace EVSS0 with VSS.
11.1 Function of A/D Converter
The A/D converter converts analog input signals into digital values, and is configured to control analog inputs, including
up to 28 channels of A/D converter analog inputs (ANI0 to ANI12 and ANI16 to ANI30). 12-bit resolution mode or 8-bit
resolution mode can also be selected by using the ADTYP bit of A/D converter mode register 2 (ADM2).
The A/D converter has the following function.
• 12-bit/8-bit resolution A/D conversion
A/D conversion is carried out repeatedly for one analog input channel selected from ANI0 to ANI12 and ANI16 to
ANI30. Each time an A/D conversion operation ends, an interrupt request signal (INTAD) is generated (when in the
select mode).
Caution The valid resolution differs depending on the voltage conditions of AV
DD and AVREFP.
For details, see 29.6.1 A/D converter characteristics.
Remark When using the converter with a resolution of 10 bits, select the 12-bit resolution mode (ADTYP = 0). Use
the higher 10 bits of the conversion result. Do not use the lower 2 bits.
<R>
<R>