
R8C/2C Group, R8C/2D Group
20. Flash Memory
Rev.2.00
Dec 05, 2007
REJ09B0339-0200
20.5
Standard Serial I/O Mode
In standard serial I/O mode, the user ROM area can be rewritten while the MCU is mounted on-board by using a
serial programmer which is suitable for the MCU.
There are three types of Standard serial I/O modes:
Standard serial I/O mode 1 ............Clock synchronous serial I/O used to connect with a serial programmer
Standard serial I/O mode 2 ............Clock asynchronous serial I/O used to connect with a serial programmer
Standard serial I/O mode 3 ............Special clock asynchronous serial I/O used to connect with a serial
programmer
This MCU uses Standard serial I/O mode 2 and Standard serial I/O mode 3.
Contact the manufacturer of your serial programmer for details. Refer to the user’s manual of your serial
programmer for instructions on how to use it.
After processing the pins shown in
Table 20.8 and rewriting the flash memory using the programmer, apply “H” to
the MODE pin and reset the hardware to run a program in the flash memory in single-chip mode.
20.5.1
ID Code Check Function
The ID code check function determines whether the ID codes sent from the serial programmer and those written
Table 20.7
Pin Functions (Flash Memory Standard Serial I/O Mode 2)
Pin
Name
I/O
Description
VCC,VSS
Power input
Apply the voltage guaranteed for programming and
erasure to the VCC pin and 0 V to the VSS pin.
VREF
Reference voltage input I
Reference voltage input pin to A/D converter and D/A
converter.
RESET
Reset input
I
Reset input pin.
P4_6/XIN
P4_6 input/clock input
I
Connect a ceramic resonator or crystal oscillator
between the XIN and XOUT pins.
P4_7/XOUT
P4_7 input/clock output I/O
P4_3/XCIN
P4_3 input/clock input
I
Connect crystal oscillator between pins XCIN and
XCOUT.
P4_4/XCOUT
P4_4 input/clock output I/O
P0_0 to P0_7
Input port P0
I
Input “H” or “L” level signal or leave the pin open.
P1_0 to P1_7
Input port P1
I
P2_0 to P2_7
Input port P2
I
P3_0 to P3_7
Input port P3
I
P4_5
Input port P4
I
P5_0 to P5_7
Input port P5
I
P6_0 to P6_5
Input port P6
I
P7_0 to P7_7
Input port P7
I
P8_0 to P8_7
Input port P8
I
P9_0 to P9_3
Input port P9
I
P6_6
TXD output
O
Serial data output pin.
P6_7
RXD input
I
Serial data input pin.
MODE
I
Input “L” level signal.