M16C6K9 Datasheet, PDF (141/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
D-A Converter
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.
DA 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
corresponding port to output mode if D-A conversion is to be performed. If D-A output is enabled, the pull-up
of corresponding port is inhibited.
Output analog voltage (V) is determined by a set value n (n : decimal) in the D-A register.
V = VREF X n/ 256 (n = 0 to 255)
VREF : reference voltage
Table.JB-1lists the performance of the D-A converter. Fig.JB-1 shows the block diagram of the D-A con-
verter. Fig.JB-2 shows the D-A control register. Fig.JB-3 shows the D-A converter equivalent circuit.
Table.JB-1 Performance of D-A converter
Item
Conversion type
Resolution
Analog output pins
R-2R type
8 bits
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
Fig.JB-1 Block diagram of D-A converter
Rev.1.00 Jun 06, 2003 page 141 of 290