M16C62_M Datasheet, PDF (459/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

D-A Converter
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
2.8 D-A Converter Usage
2.8.1 Overview of the D-A converter usage
The D-A converter used in the M16C/62A group is based on the 8-bit R-2R technique.
(1) Output voltage
The D-A converter outputs voltage within a range from 0 V to VREF. The output voltage is determined
by VREF/(256) X the D-A register contents.
The D-A converter is not effected by the Vref connection bit of the A-D converter.
(2) Conversion time
tsu = 3 µs
(3) Output from the D-A converter and the direction register
To use the D-A converter, do not set the direction register of the relevant port to output.
(4) Pins related to the D-A converter
• DA0 pin, DA1 pin Output pins of the D-A converter
• AVcc pin
The power source pin of the analog section
• VREF pin
Input pin of the reference voltage
• AVss pin
The GND pin of the analog section
(5) Registers related to the D-A converter
Figure 2.8.1 shows the memory map of D-A converter-related registers, and Figure 2.8.2 shows D-A
converter-related registers.
(6) Note
D-A output pins shared with P93 and P94. The two pins are input ports and floating at the reset.
03D816
03D916
03DA16
03DB16
03DC16
D-A register 0 (DA0)
D-A register 1 (DA1)
D-A control register (DACON)
Figure 2.8.1. Memory map of D-A converter-related registers
D-A control register
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
DACON
Address
03DC16
When reset
0016
Bit symbol
Bit name
DA0E
D-A0 output enable bit
Function
0 : Output disabled
1 : Output enabled
RW
DA1E
D-A1 output enable bit
0 : Output disabled
1 : Output enabled
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to be “0”
D-A register
b7
Symbol
Address
When reset
b0
DAi (i = 0,1) 03D816, 03DA16
Indeterminate
Function
Output value of D-A conversion
R^{R W}W
Figure 2.8.2. D-A converter-related registers
2-142