APPENDIX D LIST OF CAUTIONS
User’s Manual U18172EJ2V0UD
319
(12/15)
Chapter
Cl
assi
fi
cati
on
Function Details
of
Function
Cautions Page
Oscillation
stabilization
time on power
application or
after reset
release
The setting of this option is valid only when the crystal/ceramic oscillation clock is
selected as the system clock source. No wait time elapses if the high-speed
internal oscillation clock or external clock input is selected as the system clock
source.
p. 210
Control of
RESET pin
Because the option byte is referenced after reset release, if a low level is input to
the RESET pin before the option byte is referenced, then the reset state is not
released.
Also, when setting 0 to RMCE, connect the pull-up resistor.
p. 210
Selection of
system clock
source
Because the X1 and X2 pins are also used as the P23/ANI3 and P22/ANI2 pins,
the conditions under which the X1 and X2 pins can be used differ depending on
the selected system clock source.
(1) Crystal/ceramic oscillation clock is selected
The X1 and X2 pins cannot be used as I/O port pins or analog input pins of A/D
converter because they are used as clock input pins.
(2) External clock input is selected
Because the X1 pin is used as an external clock input pin, P121 cannot be used
as an I/O port pin or an analog input pin of A/D converter.
(3) High-speed internal oscillation clock is selected
P23/ANI3 and P22/ANI2 can be used as I/O port pins or analog input pins of A/D
converter.
p. 210
If it is selected that low-speed internal oscillator cannot be stopped, the count
clock to the watchdog timer (WDT) is fixed to low-speed internal oscillation clock.
p. 211
Low-speed
internal
oscillates
If it is selected that low-speed internal oscillator can be stopped by software,
supply of the count clock to WDT is stopped in the HALT/STOP mode, regardless
of the setting of bit 0 (LSRSTOP) of the low-speed internal oscillation mode
register (LSRCM). Similarly, clock supply is also stopped when a clock other than
the low-speed internal oscillation clock is selected as a count clock to WDT.
While the low-speed internal oscillator is operating (LSRSTOP = 0), the clock can
be supplied to the 8-bit timer H1 even in the STOP mode.
p. 211
Chapter 15
Hard
Option
byte
Caution When
the RESET Pin
Is Used as an
Inport-Only Port
Pin (P34)
Be aware of the following when erasing/writing by on-board programming using a
dedicated flash memory programmer once again on the already-written device
which has been set as "The RESET pin is used as an input-only port pin (P34)" by
the option byte function. Before supplying power to the target system, connect a
dedicated flash memory programmer and turn its power on. If the power is
supplied to the target system beforehand, it cannot be switched to the flash
memory programming mode.
p. 211
PG-FP4 GUI
software setting
value example
The above values are recommended values. Depending on the usage
environment these values may change, so set them after having performed
sufficient evaluations.
p. 218
Chapter 16
Soft
Flash
memory
Security
settings
After the security setting of the batch erase is set, erasure cannot be performed
for the device. In addition, even if a write command is executed, data different
from that which has already been written to the flash memory cannot be written
because the erase command is disabled.
p. 221