HD6473032F16 Datasheet, PDF (579/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 16 D/A Converter
16.3 Operation
The D/A converter has two built-in D/A conversion circuits that can perform conversion
independently.
D/A conversion is performed constantly while enabled in DACR. If the DADR0 or DADR1 value
is modified, conversion of the new data begins immediately. The conversion results are output
when bits DAOE0 and DAOE1 are set to 1.
An example of D/A conversion on channel 0 is given next. Timing is indicated in figure 16.2.
1. Data to be converted is written in DADR0.
2. Bit DAOE0 is set to 1 in DACR. D/A conversion starts and DA₀ becomes an output pin. The
converted result is output after the conversion time. The output value is (DADR0 contents/256)
× V_REF. Output of this conversion result continues until the value in DADR0 is modified or the
DAOE0 bit is cleared to 0.
3. If the DADR0 value is modified, conversion starts immediately, and the result is output after
the conversion time.
4. When the DAOE0 bit is cleared to 0, DA₀ becomes an input pin.
DADR0
write cycle
DACR
write cycle
DADR0
write cycle
DACR
write cycle
φ
Address
bus
DADR0
Conversion data 1
Conversion data 2
DAOE0
DA ₀
High-impedance state
Legend:
t _DCONV : D/A conversion time
t _DCONV
Conversion
result 1
Conversion
result 2
t _DCONV
Figure 16.2 Example of D/A Converter Operation
Rev. 3.00 Mar 21, 2006 page 549 of 814
REJ09B0302-0300