M16C62N Datasheet, PDF (138/213 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

D-A Converter
Mitsubishi microcomputers
M16C / 62N Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
D-A Converter
This is an 8-bit, R-2R type D-A converter. The microcomputer contains two independent D-A converters of
this type.
D-A conversion is performed when a value is written to the corresponding D-A register. Bits 0 and 1 (D-A
output enable bits) of the D-A control register decide if the result of conversion is to be output. Do not set the
target port to output mode if D-A conversion is to be performed. When the D-A output is enabled, the pull-
up function of the corresponding port is automatically disabled.
Output analog voltage (V) is determined by a set value (n : decimal) in the D-A register.
V = VREF X n/ 256 (n = 0 to 255)
VREF : reference voltage
Table 1.16.1 lists the performance of the D-A converter. Figure 1.16.1 shows the block diagram of the D-A
converter. Figure 1.16.2 shows the D-A control register. Figure J1.16.3 shows the D-A converter equiva-
lent circuit.
Table 1.16.1. Performance of D-A converter
Item
Conversion method
R-2R method
Resolution
8 bits
Analog output pin
2 channels
Performance
Data bus low-order bits
D-A register0 (8)
(Address 03D816)
R-2R resistor ladder
D-A0 output enable bit
P93/DA0
D-A register1 (8)
(Address 03DA16)
R-2R resistor ladder
D-A1 output enable bit
P94/DA1
Figure 1.16.1. Block diagram of D-A converter
137