UPD78F1502AGK-GAK-AX Datasheet, PDF (989/1031 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcontrollers

78K0R/Lx3
Function
Details of
Function
APPENDIX C LIST OF CAUTIONS
Cautions
(17/39)
Page
A/D
converter
ADS: Analog Be sure to clear bits 4 to 7 to “0”.
p.398 _†
input channel Set a channel to be used for A/D conversion in the input mode by using port mode p.398 _†
specification
registers 2 and 15 (PM2, PM15).
register
Do not set the pin that is set by ADPC as digital I/O by ADS.
p.398 _†
When using an operational amplifier n, the output signal of an operational amplifier n p.398 _†
can be used as an analog input.
ADPC: A/D port Set a channel to be used for A/D conversion in the input mode by using port mode p.399 _†
configuration registers 2 and 15 (PM2, PM15).
register
Do not set the pin that is set by ADPC as digital I/O by ADS.
p.399 _†
PM2, PM15:
If a pin is set as an analog input port, not the pin level but “0” is always read.
p.400 _†
Port mode
When an operational amplifier is used, pins AMPn+, AMPn−, and AMPnO are used, p.401 _†
registers 2 and so the alternative analog input functions cannot be used. The operational amplifier
15
output signals, however, can be used as analog inputs.
Basic operations Make sure the period of <4> to <8> is 1 μs or more.
p.404 _†
of A/D converter To use an operational amplifier output for an analog input, start operating the p.404 _†
operational amplifier before setting the A/D conversion operation (see CHAPTER 12
OPERATIONAL AMPLIFIER). Furthermore, do not change the operational amplifier
setting during the A/D conversion operation.
To use an output voltage of the voltage reference for a positive reference voltage of p.404 _†
the A/D converter, start operating the voltage reference before setting the A/D
conversion operation (see CHAPTER 13 VOLTAGE REFERENCE). Furthermore, do
not change the voltage reference setting during the A/D conversion operation.
When using the A/D converter in normal mode 2 (LV1 = 0, LV0 = 1) or low voltage p.404 _†
mode (LV1 = 1, LV0 = 0), enable the input gate voltage boost circuit for the A/D
converter by using the analog reference voltage control register (ADVRC), and then
set ADCE and ADCS to 1. After the voltage boost circuit stabilization time (10 μs)
passes after the input gate voltage boost circuit for the A/D converter has been
enabled, set ADCS to 1.
A/D conversion Make sure the period of <4> to <8> is 1 μs or more.
p.411 _†
operation
<4> may be done between <5> and <7>.
p.411 _†
<4> can be omitted. However, ignore data of the first conversion after <8> in this p.411 _†
case.
The period from <9> to <13> differs from the conversion time set using bits 5 to 1 p.411 _†
(FR2 to FR0, LV1, LV0) of ADM. The period from <12> to <13> is the conversion
time set using FR2 to FR0, LV1, and LV0.
To use an operational amplifier output for an analog input, start operating the p.411 _†
operational amplifier before setting the A/D conversion operation (see CHAPTER 12
OPERATIONAL AMPLIFIER). Furthermore, do not change the operational amplifier
setting during the A/D conversion operation.
To use an output voltage of the voltage reference for a positive reference voltage of p.411 _†
the A/D converter, start operating the voltage reference before setting the A/D
conversion operation (see CHAPTER 13 VOLTAGE REFERENCE). Furthermore, do
not change the voltage reference setting during the A/D conversion operation.
When using the A/D converter in normal mode 2 (LV1 = 0, LV0 = 1) or low voltage p.411 _†
mode (LV1 = 1, LV0 = 0), enable the input gate voltage boost circuit for the A/D
converter by using the analog reference voltage control register (ADVRC), and then
set ADCE and ADCS to 1. After the voltage boost circuit stabilization time (10 μs)
passes after the input gate voltage boost circuit for the A/D converter has been
enabled, set ADCS to 1.
R01UH0004EJ0501 Rev.5.01
973
Jun 20, 2011