Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 1625 of 1823
Jul 31, 2019
RX23W Group 45. 12-Bit D/A Converter (R12DAA)
45.3 Operation
The 12-bit D/A converter includes D/A conversion circuits for two channels, each of which can operate independently.
When the DACR.DAOEm bit (m = 0, 1) is set to 1, D/A converter is enabled and the conversion result is output.
An operation example of D/A conversion on channel 0 is shown below.
Figure 45.2 shows the timing of this operation.
(1) Set the data for D/A conversion in the DADPR.DPSEL bit and the DADR0 register.
(2) Set the DACR.DAOE0 bit to 1 to start D/A conversion. The DA0 output settles to the voltage corresponding to the
setting value after the conversion time tDCONV has elapsed. The DA0 output voltage is held at this level until the
DADR0 register is updated or the DAOE0 bit is set to 0. The output voltage (reference) is expressed by the
following formula:
Because the D/A converter output is buffered with an amplifier, the output voltage does not reach AVSS0 or
AVCC0. Refer to
section 51, Electrical Characteristics for the output voltage range.
(3) When the DADR0 register is updated, the conversion starts. The DA0 output settles at the new output voltage after
the conversion time tDCONV has elapsed.
When the DAADSCR.DAADST bit is 1 (measure against interference between D/A and A/D conversion is
enabled), it takes a maximum of one A/D conversion time for D/A conversion to start. When ADCLK is faster than
the peripheral module clock, it may take longer than one A/D conversion time.
(4) When the DAOE0 bit is set to 0, analog output is disabled.
Figure 45.2 Example of 12-Bit D/A Converter Operation
Value of DADRm register
× Reference voltage
4096
Write to
DADR0 register
Write to
DACR register
DADR0 register
DACR.DAOE0 bit
DA0 output
High-impedance state
t
DCONV
: D/A conversion time. Refer to the electric characteristics for the value.
Conversion
result (2)
Write to
DADR0 register
Write to
DACR register
Conversion
result (1)
Conversion data (1) Conversion data (2)
t
DCONV
t
DCONV

Renesas RX Series Specifications

General

Brand	Renesas
Model	RX Series
Category	Microcontrollers
Language	English