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APPENDIX B LIST OF CAUTIONS
User’s Manual U17893EJ8V0UD
858
(13/34)
Chapter
Cl
assi
fi
cati
on
Function
Details of
Function
Cautions
Page
Set the conversion times with the following conditions.
4.0 V
≤ AVREF0 ≤ 5.5 V: fAD = 0.6 to 3.6 MHz
2.7 V
≤ AVREF0 < 4.0 V: fAD = 0.6 to 1.8 MHz
2.3 V
≤ AVREF0 < 2.7 V: fAD = 0.6 to 1.44 MHz
p.318
When rewriting FR2 to FR0, LV1, and LV0 to other than the same data, stop A/D
conversion once (ADCS = 0) beforehand.
p.318
Change LV1 and LV0 from the default value, when 2.3 V
≤ AVREF0 < 2.7 V.
p.318
A/D conversion
time selection
(2.3 V
≤ AVREF0 ≤
5.5 V)
The above conversion time does not include clock frequency errors.
Select
conversion time, taking clock frequency errors into consideration.
p.318
ADCR: 10-bit
A/D conversion
result register
When writing to the A/D converter mode register (ADM), analog input channel
specification register (ADS), and A/D port configuration register (ADPC), the contents
of ADCR may become undefined. Read the conversion result following conversion
completion before writing to ADM, ADS, and ADPC.
Using timing other than the
above may cause an incorrect conversion result to be read.
p.320
ADCRH: 8-bit
A/D conversion
result register
When writing to the A/D converter mode register (ADM), analog input channel
specification register (ADS), and A/D port configuration register (ADPC), the contents
of ADCRH may become undefined. Read the conversion result following conversion
completion before writing to ADM, ADS, and ADPC.
Using timing other than the
above may cause an incorrect conversion result to be read.
p.320
Be sure to clear bits 3 to 6 to “0”.
p.321
Set a channel to be used for A/D conversion in the input mode by using port mode
registers 2 (PM2).
p.321
ADS: Analog
input channel
specification
register
Do not set the pin that is set by ADPC as digital I/O by ADS.
p.321
Set a channel to be used for A/D conversion in the input mode by using port mode
registers 2 (PM2).
p.322
Do not set the pin that is set by ADPC as digital I/O by ADS.
p.322
When all pins of ANI0/P20 to ANI7/P27 are used as digital I/O (D), ADPC4 to ADPC0
can be set by either 01000 or 10000.
p.322
ADPC: A/D port
configuration
register
P20/ANI0 to P27/ANI7 are set as analog inputs in the order of P27/ANI7, …,
P20/ANI0 by the A/D port configuration register (ADPC). When using P20/ANI0 to
P27/ANI7 as analog inputs, start designing from P27/ANI7.
p.322
PM2: Port mode
registers 2
If a pin is set as an analog input port, not the pin level but “0” is always read.
p.323
Basic operations
of A/D converter
Make sure the period of <2> to <6> is 1
μs or more.
p.324
Make sure the period of <2> to <6> is 1
μs or more.
p.328
<2> may be done between <3> and <5>.
p.328
A/D conversion
operation
The period from <7> to <10> differs from the conversion time set using bits 5 to 1
(FR2 to FR0, LV1, LV0) of ADM. The period from <9> to <10> is the conversion time
set using FR2 to FR0, LV1, and LV0.
p.328
Temperature
sensor function
The temperature sensor cannot be used when low current consumption mode is set
(RMC = 5AH) or when the internal high-speed oscillator has been stopped
(HIOSTOP = 1 (bit 0 of CSC register)). The temperature sensor can operate as long
as the internal high-speed oscillator operates (HIOSTOP = 0), even if it is not
selected as the CPU/peripheral hardware clock source.
p.329
Setting of the A/D port configuration register (ADPC), port mode register 2 (PM2) and
port register 2 (P2) is not required when using the temperature sensor. There is no
problem if the pin function is set as digital I/O.
p.330
Chapter
1
0
Soft
A/D
converter
Registers used
by temperature
sensors
Set the conversion times so as to satisfy the following condition. fAD = 0.6 to 1.8 MHz p.330