Datasheet

V850ES/JG3 CHAPTER 13 A/D CONVERTER
R01UH0015EJ0300 Rev.3.00 Page 425 of 870
Sep 30, 2010
13.5.4 Operation mode
Four operation modes are available as the modes in which to set the ANI0 to ANI11 pins: continuous select mode,
continuous scan mode, one-shot select mode, and one-shot scan mode.
The operation mode is selected by the ADA0M0.ADA0MD1 and ADA0M0.ADA0MD0 bits.
(1) Continuous select mode
In this mode, the voltage of one analog input pin selected by the ADA0S register is continuously converted into a
digital value.
The conversion result is stored in the ADA0CRn register corresponding to the analog input pin. In this mode, an
analog input pin corresponds to an ADA0CRn register on a one-to-one basis. Each time A/D conversion is
completed, the A/D conversion end interrupt request signal (INTAD) is generated. After completion of conversion,
the next conversion is started, unless the ADA0M0.ADA0CE bit is cleared to 0 (n = 0 to 11).
Figure 13-4. Timing Example of Continuous Select Mode Operation (ADA0S Register = 01H)
ANI1
A/D conversion
Data 1
(ANI1)
Data 2
(ANI1)
Data 3
(ANI1)
Data 4
(ANI1)
Data 5
(
ANI1)
Data 6
(ANI1)
Data 7
(ANI1)
Data 1 Data 2 Data 3
Data 4 Data
5
Data 6 Data 7
Data 1
(ANI1)
Data 2
(ANI1)
Data 3
(ANI1)
Data 4
(ANI1)
Data 6
(ANI1)
ADA0CR1
INTAD
Conversion start
Set ADA0CE bit = 1
Conversion start
Set ADA0CE bit = 1
(2) Continuous scan mode
In this mode, analog input pins are sequentially selected, from the ANI0 pin to the pin specified by the ADA0S
register, and their values are converted into digital values.
The result of each conversion is stored in the ADA0CRn register corresponding to the analog input pin. When
conversion of the analog input pin specified by the ADA0S register is complete, the INTAD signal is generated, and
A/D conversion is started again from the ANI0 pin, unless the ADA0CE bit is cleared to 0 (n = 0 to 11).