HD404849 Datasheet, PDF (44/125 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404849 Series
Input/Output
The MCU has 33 input/output pins (D₀–D₈, R0–R3, R6, and R7) and two input pins (D₁₀, D₁₁). The
features are described below.
• Nine pins (D₀–D₈) are high-current input/output pins.
• The D₁₀, D₁₁, R0₀–R0₂, R1–R3, R6, and R7 input/output pins are multiplexed with peripheral function
pins such as for the timers or serial interface. 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.
• Input or output selection for input/output pins and port or peripheral function selection for multiplexed
pins are set by software.
• Peripheral function output pins are CMOS output pins. Only the R2₃/SO pin can be set to NMOS open-
drain output by software.
• In stop mode, the MCU is reset, and therefore peripheral function selection is cancelled. The data
control register (DCD, DCR) is also reset, so input/output pins go to the high-impedance state.
• Each input/output pin has a built-in pull-up MOS, which can be individually turned on or off by
software.
I/O buffer configuration is shown in figure 28, programmable I/O circuits are listed in table 23, and I/O pin
circuit types are shown in table 24.
Table 23 Programmable I/O Circuits
MIS3 (bit 3 of MIS)
0
DCD, DCR
0
PDR
0
1
CMOS buffer PMOS —
—
NMOS —
—
Pull-up MOS
—
—
Note: — indicates off status.
1
1
0
0
1
0
—
On
—
On
—
—
—
—
—
1
1
0
1
—
—
On
—
On
—
On
—
On
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