HD404374 Datasheet, PDF (59/161 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip A/D Converter

HD404374/HD404384/HD404389/HD404082/HD404084 Series
Input/Output
The MCU has 20 input/output pins (D₀ to D₉, R0, R1₀, R1₃, R2₀ to R2₂, R7₀ to R7₃). The features of these
pins are described below.
• The four pins D₀ to D₃ are source large-current (10 mA max.) I/O pins.
• The four pins D₄ to D₇ are sink large-current (15 mA max.) I/O pins.
• I/O pins comprise pins (D₀, R0₀, R1₀, R1₃, R2₀ to R2₂, R7₀ to R7₃) that also have a peripheral function
(timer, serial interface, etc.). With these pins, the peripheral function setting has priority over the D port
or R port pin setting. When a peripheral function setting has been made for a pin, the pin function and
input/output mode will be switched automatically in accordance with that setting.
• Selection of input or output for I/O pins, or selection of the port or peripheral function for pins
multiplexed as peripheral function pins, is performed by the program.
• All output of the peripheral function pins are CMOS outputs. The SO pin and R2₂ port pin can be
designated as NMOS open-drain output by the program.
• A reset clears peripheral function selection. And since the data control registers (DCD, DCR) are also
reset, input/output pins go to the high-impedance state.
• Each I/O pin has a built-in pull-up MOS that can be turned on and off individually by the program.
Figure 24 shows the I/O buffer configuration, and table 22 shows I/O pin circuit configuration control by
the program.
Table 23 shows the circuit configuration of each I/O pin.
Pull-up
MOS
VCC
VCC
PMOS
Pull-up control signal
MIS3
Buffer control signal
DCD, DCR
NMOS
Output data
Input data
Input control signal
Figure 24 I/O Pin Circuit Configuration
PDR
Rev.5.00, Sep.11.2003, page 59 of 161