HD404459 Datasheet, PDF (46/122 Pages) Renesas Technology Corp – 4-bit HMCS400-series microcomputers

HD404459 Series
Input/Output
The MCU has 49 input/output pins (D₀–D₉, R0–R8, R9₀–R9₂) and 7 input pins (D₁₀, D₁₁, R9₃, RA). The
features are described as follows.
• The D₁₁, R0, R3–R6, R9₃, and RA pins are multiplexed with peripheral function pins such as those for
timers or the serial interface. See table 24. For these pins, the peripheral function setting is done prior to
the D or R port setting. Therefore, when a peripheral function is selected for a pin, the pin function and
input/output selection are automatically switched according to the setting. However, pins input to the
wakeup function are not switched. Only the valid/invalid statuses of wakeup input are controlled.
• Peripheral function output pins are CMOS out-put pins. See table 23. Only the SO pin and R4₃ port can
be set to NMOS open-drain output by software.
• In stop mode, the MCU is reset, and therefore peripheral function selection is cancelled. Input/output
pins are set at high-impedance.
• Each input/output pin has a built-in pull-up MOS (figure 29), which can be individually turned on or off
by software.
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