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CHAPTER 12 A/D CONVERTER
User’s Manual U19780EJ2V0UD
353
(10) A/D conversion result register (ADCR, ADCRH) read operation
When a write operation is performed to the A/D converter mode register 1 (ADM1), analog input channel specification
register (ADS), and A/D port configuration register (ADPC), the contents of ADCR and ADCRH may become
undefined. Read the conversion result following conversion completion before writing to ADM1, ADS, and ADPC.
Using a timing other than the above may cause an incorrect conversion result to be read.
(11) Internal equivalent circuit
The equivalent circuit of the analog input block is shown below.
Figure 12-27. Internal Equivalent Circuit of ANIn Pin
ANIn
C1
C2
R1
Table 12-7. Resistance and Capacitance Values of Equivalent Circuit (Reference Values)
AV
DD
R1
C1
C2
2.3 V
≤
AV
DD
≤
5.5 V
11.5 k
Ω
8.0 pF
8.0 pF
Remarks 1.
The resistance and capacitance values shown in Table 12-7 are not guaranteed
values.
2.
78K0/KB2-A: n = 0 to 5, 8 to 11
78K0/KC2-A: n = 0 to 6, 8 to 11, 15