HD6432345 Datasheet, PDF (532/907 Pages) Hitachi Semiconductor – H8S/2345 F-ZTAT Hardware Manual

14.5 Interrupts
The A/D converter generates an A/D conversion end interrupt (ADI) at the end of A/D conversion.
ADI interrupt requests can be enabled or disabled by means of the ADIE bit in ADCSR.
The DTC can be activated by an ADI interrupt. Having the converted data read by the DTC in
response to an ADI interrupt enables continuous conversion to be achieved without imposing a
load on software.
The A/D converter interrupt source is shown in table 14.5.
Table 14.5 A/D Converter Interrupt Source
Interrupt Source
ADI
Description
Interrupt due to end of conversion
DTC Activation
Possible
14.6 Usage Notes
The following points should be noted when using the A/D converter.
Setting Range of Analog Power Supply and Other Pins:
(1) Analog input voltage range
The voltage applied to analog input pins AN0 to AN7 during A/D conversion should be in the
range AV_SS ≤ ANn ≤ V_ref.
(2) Relation between AV_CC, AV_SS and V_CC, V_SS
As the relationship between AV_CC, AV_SS and V_CC, V_SS, set, AV_CC = V_CC and AV_SS = V_SS. If the
A/D converter is not used, the AV_CC and AV_SS pins must on no account be left open.
(3) V_ref input range
The analog reference voltage input at the V_ref pin set in the range V_ref ≤ AV_CC.
If conditions (1), (2), and (3) above are not met, the reliability of the device may be adversely
affected.
Notes on Board Design: In board design, digital circuitry and analog circuitry should be as
mutually isolated as possible, and layout in which digital circuit signal lines and analog circuit
signal lines cross or are in close proximity should be avoided as far as possible. Failure to do so
may result in incorrect operation of the analog circuitry due to inductance, adversely affecting A/D
conversion values.
519