R8C/38T-A Group
23. A/D Converter
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 541 of 730
Aug 05, 2011
Figure 23.1
A/D Converter Block Diagram
AVSS
AD
ADSTBY = 0
ADSTBY = 1
VREF
Successive
conversion register
Decoder
Vref
Vin
P1_0/AN8
CH2 to CH0 = 100b
P1_1/AN9
CH2 to CH0 = 101b
P1_2/AN10
CH2 to CH0 = 110b
P1_3/AN11
CH2 to CH0 = 111b
CKS0 to CKS2, ADCAP0, ADCAP1: Bits in ADMOD register
CH0 to CH2, SCAN0, SCAN1, ADGSEL0, ADGSEL1: Bits in ADINSEL register
ADEX0, ADSTBY, ADDDAEN, ADDDAEL: Bits in ADCON1 register
VREFMON: Bit in OCVREFCR register
Software trigger
Timer RC trigger
Trigger
P0_7/AN0
CH2 to CH0 = 000b
P0_6/AN1
CH2 to CH0 = 001b
P0_5/AN2
CH2 to CH0 = 010b
P0_4/AN3
CH2 to CH0 = 011b
P0_3/AN4
CH2 to CH0 = 100b
P0_2/AN5
CH2 to CH0 = 101b
P0_1/AN6
CH2 to CH0 = 110b
P0_0/AN7
CH2 to CH0 = 111b
CKS2 = 0
fHOCO-F
f1
CKS2 = 1
= 00b
= 01b
CH2 to CH0
SCAN1 and SCAN0
Data bus
1/2
fAD
CKS1 and CKS0
= 00b
= 01b
= 10b
= 11b
Analog circuit
ADCAP1 and ADCAP0
= 00b
= 10b
= 11b
AD0 register
AD1 register
AD2 register
AD3 register
AD4 register
AD5 register
AD6 register
AD7 register
ADGSEL1 and ADGSEL0
VREFMON = 0
VREFMON = 1
ADGSEL1 and ADGSEL0
ADEX0 = 0
ADEX0 = 1
On-chip reference voltage
(OCVREF)
(Note 1)
ADDDAEN = 0
ADDDAEN = 1
ADDDAEL
P7_0/AN12
CH2 to CH0 = 000b
P7_1/AN13
CH2 to CH0 = 001b
P7_2/AN14
CH2 to CH0 = 010b
P7_3/AN15
CH2 to CH0 = 011b
P7_4/AN16
CH2 to CH0 = 100b
P7_5/AN17
CH2 to CH0 = 101b
P7_6/AN18
CH2 to CH0 = 110b
P7_7/AN19
CH2 to CH0 = 111b
= 11b
= 10b
Event trigger from ELC
Comparator
Note:
1. When the on-chip reference voltage is used as analog input, first set the ADEX0 bit to 1 (on-chip reference voltage
selected) and then set the VREFMON bit to 1 (on-chip reference voltage and analog input are connected).
When the on-chip reference voltage is not used as analog input, first set the VREFMON bit to 0 (on-chip reference
voltage and analog input are cut off) and then set the ADEX0 bit to 0 (extended analog input pin not selected).