HD6432621 Hitachi, HD6432621 Datasheet - Page 642

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

16.5
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 16-6.
Table 16-6 A/D Converter Interrupt Source
Interrupt Source
ADI
16.6
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
(2) Relation between AVCC, AVSS and VCC, VSS
(3) Vref input range
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.
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The voltage applied to analog input pin ANn during A/D conversion should be in the range
AVSS ANn Vref.
As the relationship between AVCC, AVSS and VCC, VSS, set AVSS = VSS. If the A/D
converter is not used, the AVCC and AVSS pins must on no account be left open.
The analog reference voltage input at the Vref pin set in the range Vref
Interrupts
Usage Notes
Description
Interrupt due to end of conversion
DTC Activation
Possible
AVCC.