APPENDIX D LIST OF CAUTIONS
User’s Manual U17446EJ3V1UD
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Chapter
Cl
assi
fi
cati
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Function Details
of
Function
Cautions Page
WDTM cannot be set by a 1-bit memory manipulation instruction.
p.152
WDTM:
Watchdog timer
mode register
When using the flash memory self programming by self writing, set the
overflow time for the watchdog timer so that enough overflow time is secured
(Example 1-byte writing: 200
μ
s MIN., 1-block deletion: 10 ms MIN.).
p.152
If a value other than ACH is written to WDTE, an internal reset signal is
generated.
p.152
If a 1-bit memory manipulation instruction is executed for WDTE, an internal
reset signal is generated.
p.152
Soft
WDTE:
Watchdog timer
enable register
The value read from WDTE is 9AH (this differs from the written value (ACH)).
p.152
When “low-speed
internal oscillator
cannot be
stopped” is
selected by
option byte
In this mode, operation of the watchdog timer cannot be stopped even during
STOP instruction execution. For 8-bit timer H1 (TMH1), a division of the low-
speed internal oscillation clock can be selected as the count source, so clear
the watchdog timer using the interrupt request of TMH1 before the watchdog
timer overflows after STOP instruction execution. If this processing is not
performed, an internal reset signal is generated when the watchdog timer
overflows after STOP instruction execution.
p.153
Chapter 9
Hard
Watchdog
timer
When “low-speed
internal oscillator
can be stopped
by software” is
selected by
option byte
In this mode, watchdog timer operation is stopped during HALT/STOP
instruction execution. After HALT/STOP mode is released, counting is started
again using the operation clock of the watchdog timer set before HALT/STOP
instruction execution by WDTM. At this time, the counter is not cleared to 0
but holds its value.
p.155
Sampling time
and conversion
time
The above sampling time and conversion time do not include the clock
frequency error. Select the sampling time and conversion time such that
Notes 2 and 3 above are satisfied, while taking the clock frequency error into
consideration (an error margin maximum of
±
5% when using the high-speed
internal oscillator).
p.161
The above sampling time and conversion time do not include the clock
frequency error. Select the conversion time taking the clock frequency error
into consideration (an error margin maximum of
±
5% when using the high-
speed internal oscillator).
p.166
If a bit other than ADCS of ADM is manipulated while A/D conversion is
stopped (ADCS = 0) and then A/D conversion is started, execute two NOP
instructions or an instruction equivalent to two machine cycles, and set ADCS
to 1.
p.167
A/D conversion must be stopped (ADCS = 0) before rewriting bits FR0 to FR2. p.167
ADM: A/D
converter mode
register
Be sure to clear bits 6, 2, and 1 to 0.
p.167
ADS: Analog
input channel
specification
register
Be sure to clear bits 2 to 7 of ADS to 0.
p.167
Chapter 1
0
Soft
A/D
converter
ADCR: 10-bit A/D
conversion result
register
When writing to the A/D converter mode register (ADM) and analog input
channel specification register (ADS), the contents of ADCR may become
undefined. Read the conversion result following conversion completion before
writing to ADM and ADS. Using timing other than the above may cause an
incorrect conversion result to be read.
p.167
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