NEC 78K0R/KE3 User Manual page 837

Function Details of
Function
A/D ADS: Analog
converter input channel
specification
register
ADPC: A/D port
configuration
register
PM2: Port mode
registers 2
Basic operations
of A/D converter
A/D conversion
operation
Temperature
sensor function
Registers used
by temperature
sensors
Procedure for
using
temperature
sensors
APPENDIX B LIST OF CAUTIONS
Be sure to clear bits 3 to 6 to "0".
Set a channel to be used for A/D conversion in the input mode by using port mode
registers 2 (PM2).
Do not set the pin that is set by ADPC as digital I/O by ADS.
Set a channel to be used for A/D conversion in the input mode by using port mode
registers 2 (PM2).
Do not set the pin that is set by ADPC as digital I/O by ADS.
When using all ANI0/P20 to ANI7/P27 pins as digital I/O (D), the setting can be done
by ADPC4 to ADPC0 = either 01000 or 10000.
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.
If a pin is set as an analog input port, not the pin level but "0" is always read.
Make sure the period of <2> to <6> is 1
Make sure the period of <2> to <6> is 1
<2> may be done between <3> and <5>.
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.
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.
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.
Set the conversion times so as to satisfy the following condition. f
When rewriting FR2 to FR0, LV1, and LV0 to other than the same data, stop A/D
conversion (ADCS = 0) beforehand.
The above conversion time does not include clock frequency errors.
conversion time, taking clock frequency errors into consideration.
When using a temperature sensor, use the result of the second or later A/D
conversion for temperature sensor 0 (ANI0 side), and the result of the third or later
A/D conversion for temperature sensor 1 (ANI1 side).
Be sure to clear bits 4 to 6 to "0".
Make sure the period of <2> to <5> is 1
the result of the third and later conversion becomes valid on the sensor 0 side.
<2> can be done between <3> and <4>.
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.
Do not change the AV voltage during <4> to <13>. Although the temperature
REF
sensor detection value does not depend on the AV
problem even if the AV voltage varies at every temperature measurement, it must
REF
be stable during a measurement cycle (from <4> to <13>).
User's Manual U17854EJ9V0UD
Cautions
μ
s or more.
μ
s or more.
= 0.6 to 1.8 MHz p.319
AD
μ
s or more. If ADCS is set to 1 within 1
voltage and thus there is no
REF
(13/33)
Page
p.310
p.310
p.310
p.311
p.311
p.311
p.311
p.312
p.313
p.317
p.317
p.317
p.318
p.319
p.319
Select p.319
p.320
p.320
μ
s, p.324
p.324
p.324
p.324
837