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4554 Datasheet, PDF (5/138 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER | |||
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4554 Group
PIN DESCRIPTION
Pin
Name
VDD
Power supply
VSS
Ground
CNVSS
CNVSS
VDCE
Voltage drop
detection circuit
enable
RESET
Reset input/output
XIN
XOUT
XCIN
XCOUT
D0âD7
D8, D9
Main clock input
Main clock output
Sub-clock input
Sub-clock output
I/O port D
Input is examined by
skip decision.
Output port D
P00âP03 I/O port P0
P10âP13 I/O port P1
P20âP23 Input port P2
P30âP33 Input port P3
Port C
Output port C
COM0â
COM3
Common output
SEG0âSEG31 Segment output
VLC3âVLC1 LCD power supply
CNTR0,
CNTR1
Timer input/output
INT0, INT1 Interrupt input
Input/Output
Function
â
Connected to a plus power supply.
â
Connected to a 0 V power supply.
â
Connect CNVSS to VSS and apply âLâ (0V) to CNVSS certainly.
Input
This pin is used to operate/stop the voltage drop detection circuit. When âHâ level is
input to this pin, the circuit starts operating. When âLâ level is input to this pin, the
circuit stops operating.
I/O
An N-channel open-drain I/O pin for a system reset. When the watchdog timer, the
built-in power-on reset or the voltage drop detection circuit causes the system to be
reset, the RESET pin outputs âLâ level.
Input
Output
I/O pins of the main clock generating circuit. When using a ceramic resonator, con-
nect it between pins XIN and XOUT. A feedback resistor is built-in between them.
When using the RC oscillation, connect a resistor and a capacitor to XIN, and leave
XOUT pin open.
Input I/O pins of the sub-clock generating circuit. Connect a 32 kHz quartz-crystal oscillator
Output between pins XCIN and XCOUT. A feedback resistor is built-in between them.
I/O
Each pin of port D has an independent 1-bit wide I/O function. The output structure
can be switched to N-channel open-drain or CMOS by software. For input use, set
the latch of the specified bit to â1â and select the N-channel open-drain. Port D7 is
also used as CNTR0 pin.
Output
Each pin of port D has an independent 1-bit wide output function. The output struc-
ture is N-channel open-drain. Ports D8 and D9 are also used as INT0 pin and INT1
pin, respectively.
I/O
Port P0 serves as a 4-bit I/O port. The output structure can be switched to N-channel
open-drain or CMOS by software. For input use, set the latch of the specified bit to
â1â and select the N-channel open-drain. Port P0 has a key-on wakeup function and
a pull-up function. Both functions can be switched by software.
I/O
Port P1 serves as a 4-bit I/O port. The output structure can be switched to N-channel
open-drain or CMOS by software. For input use, set the latch of the specified bit to
â1â and select the N-channel open-drain. Port P1 has a key-on wakeup function and
a pull-up function. Both functions can be switched by software.
Input
Port P2 serves as a 4-bit input port.
Ports P20âP23 are also used as SEG31âSEG28, respectively.
Input
Port P3 serves as a 4-bit input port.
Ports P30âP33 are also used as SEG27âSEG24, respectively.
Output 1-bit output port. The output structure is CMOS. Port C is also used as CNTR1 pin.
Output LCD common output pins. Pins COM0 and COM1 are used at 1/2 duty, pins COM0â
COM2 are used at 1/3 duty and pins COM0âCOM3 are used at 1/4 duty.
Output LCD segment output pins. SEG0âSEG2 pins are used as VLC3âVLC1 pins, respectively.
â
LCD power supply pins.
When the internal resistor is used, VDD pin is connected to VLC3 pin (if luminance ad-
justment is required, VDD pin is connected to VLC3 pin through a resistor).
When the external power supply is used, apply the voltage 0 ⤠VLC1 ⤠VLC2 ⤠VLC3 ⤠VDD.
VLC3âVLC1 pins are used as SEG0âSEG2 pins, respectively.
I/O
CNTR0 pin has the function to input the clock for the timer 1 event counter, and to
output the timer 1 or timer 2 underflow signal divided by 2.
CNTR1 pin has the function to input the clock for the timer 3 event counter, and to
output the PWM signal generated by timer 4.CNTR0 pin and CNTR1 pin are also
used as Ports D7 and C, respectively.
Input
INT0 pin and INT1 pin accept external interrupts. They have the key-on wakeup func-
tion which can be switched by software. INT0 pin and INT1 pin are also used as
Ports D8 and D9, respectively.
Rev.3.00 Aug 06, 2004 page 5 of 136
REJ03B0043-0300Z
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