MC-78F0712-KIT Renesas Electronics America, MC-78F0712-KIT Datasheet - Page 206

• Manufacturer Part Number: MC-78F0712-KIT
• Description: KIT REF SYSTEM 78K0 UPD78F0712
• Manufacturer: Renesas Electronics America

Specifications of MC-78F0712-KIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

204
(a) Controlling reference voltage generator for boosting
When the ADCS2 bit = 0, power to the A/D converter drops. The converter requires a setup time of 1 s or
more after the ADCS2 bit has been set to 1.
Therefore, the result of A/D conversion becomes valid from the first result by setting the ADCS bit to 1 at
least 1 s after the ADCS2 bit has been set to 1.
Notes 1. If the ADCS and ADCS2 bits are changed from 00B to 10B, the reference voltage generator for
Note The time from the rising of the ADCS2 bit to the falling of the ADCS bit must be 1 s or longer to
Cautions 1. A/D conversion must be stopped before rewriting bits FR0 to FR2, ADHS0, and ADHS1
Boost reference voltage
ADCS
0
0
1
1
stabilize the reference voltage.
2. If the ADCS and ADCS2 bits are changed from 00B to 11B, the reference voltage generator for
Figure 13-4. Timing Chart When Boost Reference Voltage Generator Is Used
boosting automatically turns on. If the ADCS bit is cleared to 0 while the ADCS2 bit is 0, the
voltage generator automatically turns off. In the software trigger mode (ADS.TRG bit = 0), use of
the first A/D conversion result is prohibited.
In the hardware trigger mode (TRG bit = 1), use the A/D conversion result only if A/D conversion is
started after the lapse of the oscillation stabilization time of the reference voltage generator for
boosting.
boosting automatically turns on. If the ADCS bit is cleared to 0 while the ADCS2 bit is 1, the
voltage generator stays on. In the software trigger mode (TRG bit = 0), use of the first A/D
conversion result is prohibited.
In the hardware trigger mode (TRG bit = 1), use the A/D conversion result only if A/D conversion is
started after the lapse of the oscillation stabilization time of the reference voltage generator for
boosting.
2. If data is written to ADM, a wait cycle is generated. For details, see CHAPTER 27
to values other than the identical data.
CAUTIONS FOR WAIT.
ADCS2
ADCS2
ADCS
0
1
0
1
Stop status (DC power consumption path does not exist)
Conversion waiting mode (only reference voltage generator consumes power)
Conversion mode (reference voltage generator operation stopped
Conversion mode (reference voltage generator operates
Table 13-2. Settings of ADCS and ADCS2
Note
Boost reference voltage generator: operating
CHAPTER 13 A/D CONVERTER
Conversion
operation
User’s Manual U17890EJ2V0UD
Conversion
A/D Conversion Operation
waiting
Conversion
operation
Note 2
)
Conversion stopped
Note 1
)