Interrupts; Usage Notes - Renesas F-ZTAT H8 Series Hardware Manual

Section 15 A/D Converter
15.5

Interrupts

The A/D converter generates an interrupt (ADI) at the end of A/D conversion. The ADI interrupt
request can be enabled or disabled by the ADIE bit in ADCSR.
15.6

Usage Notes

When using the A/D converter, note the following points:
1. Analog Input Voltage Range: During A/D conversion, the voltages input to the analog input
pins should be in the range AV
2. Relationships of AV
as follows: AV = V
SS
used.
3. V Programming Range: The reference voltage input at the V
REF
≤ AV
V .
REF CC
4. Analog Voltage: When using an A/D converter, make the following voltage settings.
≥ AV
a. V – 0.3V
CC CC
≥ V ≥ ANn ≥ AV
b. AV
CC REF
(N = 0 to 7)
Note: Restriction for the ZTAT version only; The S-mask version of ZTAT, the Flash
Memory version and Mask ROM version can be used regularly without restriction.
Failure to observe points 1, 2, 3, and 4 above may degrade chip reliability.
5. Note on Board Design: In board layout, separate the digital circuits from the analog circuits as
much as possible. Particularly avoid layouts in which the signal lines of digital circuits cross or
closely approach the signal lines of analog circuits. Induction and other effects may cause the
analog circuits to operate incorrectly, or may adversely affect the accuracy of A/D conversion.
The analog input signals (AN
voltage (AV ) must be separated from digital circuits by the analog ground (AV
CC
analog ground (AV
board.
Rev. 7.00 Sep 21, 2005 page 550 of 878
REJ09B0259-0700
≤ AN ≤ V
SS n
and AV to V and V
CC SS CC
. AV and AV
SS CC SS
= V
SS SS
to AN ), analog reference voltage (V
0 7
) should be connected to a stable digital ground (V
SS
.
REF
: AV , AV , V
SS CC SS
must not be left open, even if the A/D converter is not
, and V should be related
CC SS
pin should be in the range
REF
), and analog supply
REF
). The
SS
) at one point on the
SS