4571 Datasheet, PDF (5/126 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4571 Group
PIN DESCRIPTION
Table 3 Pin description
Pin
VDD
VSS
RESET
Name
Power source
Power source
Reset I/O
XIN
XOUT
D0−D4
Main clock input
Main clock output
I/O port D
(Input is examined
by skip decision.)
P00−P03 I/O port P0
P10−P13 I/O port P1
P20, P21 I/O port P2
P30, P31 I/O port P3
C
Output port C
K
Input port K
CNTR0,
CNTR1
Timer I/O
INT0, INT1 Interrupt input
Input/Output
Function
−
Connected to a plus power supply.
−
Connected to a 0 V power supply.
I/O
An N-channel open-drain I/O pin for a system reset. When the SRST instruction,
watchdog timer, or the built-in power-on reset causes the system to be reset, the RESET
pin outputs “L” level.
Input
Output
I/O pins of the main clock generating circuit. Connect a ceramic resonator between pins
XIN and XOUT. 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 of ports D0–D3 can be switched to N-channel open-drain or CMOS
by software.
For input use, set the latch of the specified bit to “1” and select the N-channel open-drain.
Port D4 is also used as CNTR0 pin.
I/O
Port P0 serves as a 4-bit I/O port. The output structure is 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 is N-channel open-drain.
Port P1 has a key-on wakeup function and a pull-up function.
Both functions can be switched by software.
I/O
Port P2 serves as a 2-bit I/O port. The output structure is N-channel open-drain.
For input use, set the latch of the specified bit to “1”.
Ports P20 and P21 are also used as INT0 pin and INT1 pin, respectively.
I/O
Port P3 serves as a 2-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 “1”.
Output
Port C serves as a 1-bit output port.
The output structure is CMOS. Port C is also used as CNTR1.
Input
Port K serves as a 1-bit input port.
It has the key-on wakeup function which can be switched by software.
When port K is used for the input of key matrix, connect a pull-up resistor to it externally.
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 output the PWM signal generated by timer 3.
CNTR0 pin and CNTR1 pin are also used as Ports D4 and C, respectively.
Input
INT0 pin and INT1 pin accept external interrupts.
They have the key-on wakeup function which can be switched by software.
INT0 pin and INT1 pin are also used as Ports P20 and P21, respectively.
MULTIFUNCTION
Table 4 Pin description
Pin
Multifunction
Pin
Multifunction
Pin
Multifunction
Pin
Multifunction
C
CNTR1
P20
INT0
CNTR1
C
INT0
P20
D4
CNTR0
P21
INT1
CNTR0
D4
INT1
P21
Note 1.Pins except above have just single function.
Note 2.The input of D4 can be used even when CNTR0 (output) is selected.
The input/output of D4 can be used even when CNTR0 (input) is selected.
Be careful when using inputs of both CNTR0 and D4 since the input threshold value of CNTR0 pin is different from that of port D4.
Note 3.“H” output function of port C can be used even when the CNTR1 (output) is used.
Note 4.The input/output of P20 can be used even when INT0 is used.
Be careful when using inputs of both INT0 and P20 since the input threshold value of INT0 pin is different from that of port P20.
Note 5.The input/output of P21 can be used even when INT1 is used.
Be careful when using inputs of both INT1 and P21 since the input threshold value of INT1 pin is different from that of port P21.
Rev.1.02 May 25, 2007 Page 5 of 124
REJ03B0179-0102