R01UH0822EJ0100 Rev.1.00
Page 879 of 1041
Jul 31, 2019
RX13T Group
26. 12-Bit A/D Converter (S12ADF)
26.6
Usage Notes
26.6.1
Notes on Reading Data Registers
The A/D data registers, A/D data duplication registers, A/D data duplication register A, A/D data duplication register B
A/D internal reference voltage data register, and A/D self-diagnosis data register should be read in 16-bit units. If a
register is read twice in 8-bit units, that is, the higher-order byte and lower-order byte are separately read, the A/D-
converted value having been read first may disagree with the A/D-converted value having been read for the second time.
To prevent this, the data registers should never be read in 8-bit units.
26.6.2
Notes on Stopping A/D Conversion
To stop A/D conversion when an asynchronous trigger or a synchronous trigger has been selected as the condition for
starting A/D conversion, follow the procedure in
Figure 26.33
Procedure for Clear Operation by Software through the ADCSR.ADST Bit
To disable trigger inputs, set the ADSTRGR register to
3F3Fh (set the TRSA[5:0] and TRSB[5:0] bits to 3Fh
and 3Fh, respectively)
Is the ADGSPCR.PGS bit set to 1?
No
Yes
Set the ADGSPCR.PGS bit to 0
Are the ADCSR.ADCS[1:0] bits set to 01b
(group scan mode)?
To disable trigger inputs, set the
ADSTRGR.TRSA[5:0] bits to 3Fh
Is the group C used
(ADGCTRGR.GRCE = 1)?
Start
Yes
No
Yes
No
Set the ADGCTRGR.TRSC[5:0] bits to 3Fh
Set the ADCSR.ADST bit to 0 to perform software clear
operation. Stop A/D conversion
End