
22
Table 1-4
HD404344R and HD404394 Series Pin Functions (cont)
Type
Symbol
I/O
Function
Port
R2
0 to R23
I/O
R2 port (HD404344R Series): I/O pins (CMOS three
state) that can be accessed as a 4-bit unit. Pins R2
0 to
R2
3 are high current pins that can accept influx currents
of up to 15 mA.
R2 port (HD404394 Series): I/O pins (NMOS open
drain) that can be accessed as a 4-bit unit.
Pins R2
0 to R23 are high current pins that can accept
influx currents of up to 15 mA.
R3
0 to R33,
(R3
1 to R33)*
I/O
R3 port: Standard I/O pins (CMOS three state) that
can be accessed as a 4-bit (3-bit)* unit.
System control
TEST
Input
Test: Connect to ground.
RESET
Input
Reset: The microcomputer goes to the reset state
when a low level is applied to this pin.
STOPC
Input
Stop mode clear: Input pin for clearing stop mode.
The microcomputer switches from stop mode to active
mode when a low level is applied to this pin.
Interrupt
INT
0
Input
External interrupt input 0: Falling edge detection
external interrupt input.
8-bit timers
TOC
Output Timer C output: The timer C output. Generates a
PWM output signal.
EVNB
Input
Timer B event input: The timer B event input. External
events can be counted on falling edges, rising edges,
or falling/rising edge pairs in this input.
Serial interface
SCK
I/O
Serial transfer clock I/O: I/O pin for the serial
interface clock.
SI
Input
Serial reception data input: Data input pin for the
serial interface.
SO
Output Serial transmission output: Data output pin for the
serial interface.
A/D converter
AN
0 to AN3
(AN
1 to AN3)*
Input
Analog input channels 0 to 3 (HD404344R Series):
Analog input channels for the A/D converter.
Analog input channels 1 to 3 (HD404394 Series):
Analog input channels for the A/D converter.
Note: * Items without parentheses apply to the HD404344R Series and items in parentheses apply
to the HD404394 Series.