
CHAPTER 13 A/D CONVERTER
User’s Manual U16541EJ4V0UD
470
(1) Continuous select mode
In this mode, the result of converting the voltage of the analog input pin specified by the ADA0S register is
compared with the set value of the ADA0PFT register. If the result of power-fail comparison matches the
condition set by the ADA0PFC bit, the conversion result is stored in the ADA0CRn register, and the INTAD
signal is generated. If it does not match, the conversion result is stored in the ADA0CRn register, and the
INTAD signal is not generated. After completion of the first conversion, the next conversion is started, unless
the ADA0M0.ADA0CE bit is cleared to 0 (n = 0 to 11).
Figure 13-8. Timing Example of Continuous Select Mode Operation
(When Power-Fail Comparison Is Made: 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
ADA0PFT
unmatch
ADA0PFT
unmatch
ADA0PFT
match
ADA0PFT
match
ADA0PFT
match
Conversion start
Set ADA0CE bit = 1
(2) Continuous scan mode
In this mode, the results of converting the voltages of the analog input pins sequentially selected from the ANI0
pin to the pin specified by the ADA0S register are stored, and the set value of the ADA0CR0H register of
channel 0 is compared with the value of the ADA0PFT register. If the result of power-fail comparison matches
the condition set by the ADA0PFC bit, the conversion result is stored in the ADA0CR0 register, and the INTAD
signal is generated. If it does not match, the conversion result is stored in the ADA0CR0 register, and the
INTAD signal is not generated.
After the result of the first conversion has been stored in the ADA0CR0 register, the results of sequentially
converting the voltages on the analog input pins up to the pin specified by the ADA0S register are continuously
stored. After completion of conversion, the next conversion is started from the ANI0 pin again, unless the
ADA0CE bit is cleared to 0.