Datasheet

R8C/28 Group, R8C/29 Group 1. Overview
Rev.2.10 Sep 26, 2008 Page 8 of 67
REJ03B0169-0210
1.6 Pin Functions
Table 1.5 lists Pin Functions.
I: Input O: Output I/O: Input and output
Table 1.5 Pin Functions
Type Symbol I/O Type Description
Power supply input VCC, VSS I Apply 2.2 to 5.5 V (J, K version are 2.7 to 5.5 V) to the VCC
pin. Apply 0 V to the VSS pin.
Analog power
supply input
AVCC, AVSS I Power supply for the A/D converter.
Connect a capacitor between AVCC and AVSS.
Reset input
RESET
I Input “L” on this pin resets the MCU.
MODE MODE I Connect this pin to VCC via a resistor.
XIN clock input XIN I These pins are provided for XIN clock generation circuit I/O.
Connect a ceramic resonator or a crystal oscillator between
the XIN and XOUT pins. To use an external clock, input it to
the XIN pin and leave the XOUT pin open.
XIN clock output XOUT O
XCIN clock input
(N, D version)
XCIN I These pins are provided for XCIN clock generation circuit I/O.
Connect a crystal oscillator between the XCIN and XCOUT
pins. To use an external clock, input it to the XCIN pin and
leave the XCOUT pin open.
XCIN clock output
(N, D version)
XCOUT O
INT
interrupt input INT0, INT1, INT3 IINT interrupt input pins
Key input interrupt
KI0
to KI3
I Key input interrupt input pins
Timer RA TRAO O Timer RA output pin
TRAIO I/O Timer RA I/O pin
Timer RB TRBO O Timer RB output pin
Timer RC TRCCLK I External clock input pin
TRCTRG I External trigger input pin
TRCIOA, TRCIOB,
TRCIOC, TRCIOD
I/O Sharing output-compare output / input-capture input / PWM /
PWM2 output pins
Serial interface CLK0 I/O Clock I/O pin
RXD0, RXD1 I Receive data input pin
TXD0, TXD1 O Transmit data output pin
I
2
C bus interface
SCL I/O Clock I/O pin
SDA I/O Data I/O pin
Clock synchronous
serial I/O with chip
select
SSI I/O Data I/O pin
SCS
I/O Chip-select signal I/O pin
SSCK I/O Clock I/O pin
SSO I/O Data I/O pin
Reference voltage
input
VREF I Reference voltage input pin to A/D converter
A/D converter AN8 to AN11 I Analog input pins to A/D converter
I/O port P1_0 to P1_7,
P3_3 to P3_5, P3_7,
P4_5
I/O CMOS I/O ports. Each port has an I/O select direction
register, allowing each pin in the port to be directed for input
or output individually.
Any port set to input can be set to use a pull-up resistor or not
by a program.
P1_0 to P1_7 also function as LED drive ports (N, D version).
Input port P4_2, P4_6, P4_7 I Input-only ports