HD64F2145 Datasheet, PDF (596/829 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

20.4 Operation
The D/A converter incorporates two channels of the D/A circuits and can be converted
individually.
When the DAOE bit in DACR is set to 1, D/A conversion is enabled and conversion results are
output.
An example of D/A conversion of channel 0 is shown below. The operation timing is shown in
figure 20.2.
1. Write conversion data to DADR0.
2. When the DAOE0 bit in DACR is set to 1, D/A conversion starts. After the interval of t , _DCONV
conversion results are output from the analog output pin DA0. The conversion results are
output continuously until DADR0 is modified or the DAOE0 bit is cleared to 0. The output
value is calculated by the following formula:
DADR contents/256 × AVref
3. Conversion starts immediately after DADR0 is modified. After the interval of t , _DCONV
conversion results are output.
4. When the DAOE0 bit is cleared to 0, analog output is disabled.
DADR0
write cycle
DACR
write cycle
ø
DADR0
write cycle
DACR
write cycle
Address
DADR0
Conversion data (1)
Conversion data (2)
DAOE0
DA0
High impedance state
Legend
tDCONV: D/A conversion time
t_DCONV
Conversion result (1)
t_DCONV
Conversion
result (2)
Figure 20.2 D/A Converter Operation Example
Rev. 2.0, 08/02, page 556 of 788