
TC94A23F
2002-02-06
7
Pin
Number
Symbol
Pin Name
Function and Operation
Remarks
21~24
P1-0~P1-3
I/O port 1
4-bit CMOS I/O port.
Input/output can be set for each bit by
program.
The pins can be set to be pulled-up or
pulled-down by program. Thus, they can be
used as key input pins. When the pins are set
to I/O port input, Clock Stop mode and Wait
mode can be released, according to the
change in input to the pins.
25
P3-0
I/O port 3
26~28
P3-1/ADin1
~
P3-3/ADin3
I/O port 3
/A/D analog voltage
input
29
P4-0/ADin4
/BUZR
I/O port 4
/A/D analog voltage
input/buzzer output
5-bit CMOS I/O port.
Input/output can be set for each bit by
program.
P3-1 and P4-0 pins are also used as built-in
6-bit 4-channel A/D converter analog input
pins.
The built-in A/D converter uses successive
approximation. The conversion time is 6
instruction cycles (280 s) when the 75 kHz
crystal oscillator is used; 198 s when the 4.5
MHz crystal oscillator is used; 180 s when
the 16.9344 MHz crystal oscillator is used.
A/D analog input can be set for each pin by
program. The internal power supply (MV
DD
) is
used as the reference voltage.
The P4-0 pin is also used as the buzzer
output pin.
One of four frequencies: 0.75, 1, 1.5, and 3
kHz, can be selected for buzzer output. The
buzzer is output at the selected frequency in
one of four modes: Continuous, single-shot,
10 Hz intermittent, and 10 Hz intermittent at 1
Hz interval.
Settings for the A/D converter and buzzer,
and their control can be performed by
program.
33
P2-0/EMPHin
34
P2-1/
HSO
in
35
P2-2/LRCKin
36
P2-3/DATAin
I/O port 2
/1-bit DAC input
37
IN1/BCKin
89
IN2/ (VPP)
General-purpose
input port/1-bit DAC
input (VPP input)
I/O port 2 is a 4-bit CMOS I/O port.
IN1 and IN2 are a 2-bit general-purpose input
port.
Input/output can be set for each bit of I/O port
2 by program.
I/O port 2 and the IN1 pins can be switched to
1-bit DAC input pins by the CD command to
support shock-proofing. In this case, the I/O
port must be set to input.
With the OTP version, the IN2 pin is also used
as the program power supply pin.
MV
DD
MV
DD
R
IN1
MV
DD
MV
DD
To A/D
converter
Input
instruction
MV
DD
MV
DD
MV
DD