APPENDIX D LIST OF CAUTIONS
User’s Manual U16899EJ2V0UD
536
(22/24)
Chapter
Cl
assi
fi
cati
on
Function Details
of
Function
Cautions Page
Soft
If an internal reset signal is generated in the POC circuit, the reset control flag
register (RESF) is cleared to 00H.
p. 404
Hard
Power-on-clear
circuit functions
The supply voltage is V
DD
= 2.0 to 5.5 V when the Ring-OSC clock or subsystem
clock is used, but be sure to use the product in a voltage range of 2.2 to 5.5 V
because the detection voltage (V
POC
) of the POC circuit is 2.1 V
±
0.1 V.
p. 404
Chapter 22
Soft
Power-
on-clear
circuit
(POC)
Cautions for
power-on-clear
circuit
In a system where the supply voltage (V
DD
) fluctuates for a certain period in the
vicinity of the POC detection voltage (V
POC
), the system may be repeatedly reset
and released from the reset status. In this case, the time from release of reset to
the start of the operation of the microcontroller can be arbitrarily set by taking the
following action.
p. 406
LVIM: Low-
voltage
detection
register
To stop LVI, follow either of the procedures below.
•
When using 8-bit memory manipulation instruction: Write 00H to LVIM.
•
When using 1-bit memory manipulation instruction: Clear LVION to 0.
p. 409
LVIS: Low-
voltage
detection level
selection
register
Be sure to clear bits 4 to 7 to 0.
p. 410
<1> must always be executed. When LVIMK = 0, an interrupt may occur
immediately after the processing in <3>.
p. 411
When used as
reset
If supply voltage (V
DD
)
≥
detection voltage (V
LVI
) when LVIMD is set to 1, an
internal reset signal is not generated.
p. 411
Chapter 23
Soft
Low-
voltage
detector
(LVI)
Cautions for
low-voltage
detector
In a system where the supply voltage (V
DD
) fluctuates for a certain period in the
vicinity of the LVI detection voltage (V
LVI
), the operation is as follows depending
on how the low-voltage detector is used.
(1) When used as reset
The system may be repeatedly reset and released from the reset status.
In this case, the time from release of reset to the start of the operation of the
microcontroller can be arbitrarily set by taking action (a) below.
(2) When used as interrupt
Interrupt requests may be frequently generated. Take action (b) below.
p. 415
To use the boot swap function, be sure to store the option data in the boot cluster
1 (for the boot swap function, see 26.9 Boot Swap Function).
p. 418
Chapter 24
Hard
Option
byte
−
Be sure to clear bits 1 to 7 to 0.
p. 418
Hard
−
The ROM correction cannot be emulated by the in-circuit emulator.
p. 419
Set the CORAD0 and CORAD1 when bit 1 (COREN0) and bit 3 (COREN1) of the
correction control register (CORCN: see Figure 25-3) are 0.
p. 420
Only addresses where operation codes are stored can be set in CORAD0 and
CORAD1.
p. 420
Chapter 25
Soft
ROM
correction
CORAD0,
CORAD1:
Correction
address
registers 0 and
1
Do not set the following addresses to CORAD0 and CORAD1.
•
Address value in table area of table reference instruction (CALLT instruction):
0040H to 007FH
•
Address value in vector table area: 0000H to 003FH
p. 420