CHAPTER 12 A/D CONVERTER
Preliminary User’s Manual U16315EJ1V0UD
229
Table 12-2. Settings of ADCS and ADCE
ADCS
ADCE
A/D Conversion Operation
0
0
Stop status (DC power consumption path does not exist)
0
1
Conversion waiting mode (only reference voltage generator consumes power)
1
0
Conversion mode (reference voltage generator operation stopped
Note
)
1
1
Conversion mode (reference voltage generator operates)
Note
Data of first conversion cannot be used.
Figure 12-5. Timing Chart When Boost Reference Voltage Generator Is Used
ADCE
Boost reference voltage
ADCS
Conversion
operation
Conversion
operation
Conversion stopped
Conversion
waiting
Boost reference voltage generator: operating
Note
Note
14
µ
s or more is required for reference voltage stabilization.
Cautions 1. A/D conversion must be stopped before rewriting bits FR0 to FR2 to values other than the
identical data.
2. For the sampling time of the A/D converter and the A/D conversion start delay time, refer to
(11) in 12.6 Cautions for A/D Converter.
3. If data is written to ADM, a wait cycle is generated. Do not write data to ADM when the CPU
is operating on the subsystem clock and the X1 input clock is stopped. For details, refer to
CHAPTER 29 CAUTIONS FOR WAIT.
Remark
f
X
: X1 input clock oscillation frequency