Timing Chart When Boost Reference Voltage Generator Is Used - NEC 78K0 User Manual

ADCS ADCE
0
0
1
1
Note Data of first conversion cannot be used.
Figure 13-3. Timing Chart When Boost Reference Voltage Generator Is Used
ADCE
Boost reference voltage
ADCS
Note The time from the rising of the ADCE bit to the falling of the ADCS bit must be 14
the reference voltage.
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, see (11)
in 13.6 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.
CHAPTER 35 CAUTIONS FOR WAIT.
Remark f : X1 input clock oscillation frequency
X
282
CHAPTER 13 A/D CONVERTER
Table 13-2. Settings of ADCS and ADCE
0 Stop status (DC power consumption path does not exist)
1 Conversion waiting mode (only reference voltage generator consumes power)
0 Conversion mode (reference voltage generator operation stopped
1 Conversion mode (reference voltage generator operates)
Boost reference voltage generator: operating
Conversion
operation
Note
User's Manual U15947EJ2V0UD
A/D Conversion Operation
Conversion Conversion
waiting operation
*
Note
)
Conversion stopped
µ
s or longer to stabilize
For details, see