M32C80 Datasheet, PDF (255/352 Pages) Renesas Technology Corp – 16/32-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M32C/80 SERIES

M32C/80 Group
18. D/A Converter
18. D/A Converter
The D/A converter consists of two separate 8-bit R-2R ladder D/A converters.
Digital code is converted to an analog voltage when a value is written to the corresponding DAi registers
(i=0,1). The DAiE bit in the DACON register determines whether the D/A conversion result output is pro-
vided or not. Set the DAiE bit to "1" (output enabled) to disable a pull-up of a corresponding port.
Output analog voltage (V) is calculated from value n (n=decimal) set in the DAi register.
V = ^{VREF x n} (n = 0 to 255)
256
VREF : reference voltage (not related to VCUT bit setting in the AD0CON1 register)
Table 18.1 lists specifications of the D/A converter. Table 18.2 lists the DA0 and DA1 pin settings. Figure
18.1 shows a block diagram of the D/A converter. Figure 18.2 shows the D/A control register. Figure 18.3
shows a D/A converter equivalent circuit.
When the D/A converter is not used, set the DAi register to "0016" and the DAiE bit to "0" (output disabled).
Table 18.1 D/A Converter Specifications
Item
D/A Conversion Method
Resolution
Analog Output Pin
R-2R
8 bits
2 channels
Specification
Table 18.2 Pin Settings
Port
Function
Setting
PD9 Register⁽¹⁾
PS3 Register⁽¹⁾
PSL3 Register
P93
DA0 output
PD9_3=0
PS3_3=0
PSL3_3=1
P94
DA1 output
PD9_4=0
PS3_4=0
PSL3_4=1
NOTE:
1. Set the PD9 and PS3 registers immediately after the PRC2 bit in the PRCR register is set to "1" (write
enable). Do not generate an interrupt or a DMA transfer between the instruction to set the PRC2 bit to "1"
and the instruction to set the PD9 and PS3 registers.
Rev. 1.00 Nov. 01, 2005 ^{Page 236} of 330
REJ09B0271-0100