E202075_HD404889 Datasheet, PDF (69/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
Input/Output
The MCU has 46 input/output pins (D₀ to D₁₁, R0 to R7, R8₀, and R8₁) in the HD404889, HD404899, and
HD404878 Series, or 41 input/output pins (D₀ to D₉, R0₀, R0₁, R0₂, and R1 to R7) in the HD404868 Series.
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 eight pins D₄ to D₁₁ are sink large-current (15 mA max.) I/O pins.
• I/O pins comprise pins (D₀, D₁, R₀, R₁, R2₀ to R2₂, R3 to R7, R8₀, and R8₁) 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 26 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 26 I/O Pin Circuit Configuration
PDR
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