TC1796
Peripheral Units (Vol. 2 of 2)
Analog-to-Digital Converter (ADC)
User’s Manual
25-113
V2.0, 2007-07
ADC, V2.0
25.3.6
On-Chip Connections
This section describes the on-chip interconnections of the ADC0/ADC1 modules.
25.3.6.1 Reference Voltage Selection
Generally, the ADC modules allow the analog reference voltage for each analog channel
to be selected via the CHCONn.REF bit field. In the TC1796, only ADC0 is able to select
among three analog reference voltages:
V
AREF0
, AIN0, and AIN1 (see
). In
ADC1 always
V
AREF1
is selected as analog reference voltage source.
Note: The selections ADC0_CHCONn.REF = 11
B
must not be used. The settings of bit
fields ADC1_CHCONn.REF are “don’t care”.
Figure 25-33 ADC0/ADC1 Reference Voltage Selections
MCA06036
AIN0
AIN31
AIN1
AIN2
MUX
V
AREF
[0]
A/D
Converter
V
AREF
[1]
V
AREF
[2]
V
AREF0
V
AGND0
ADC0
REF
ADC0_CHCONn
V
AREF1
V
AGND1
ADC1
N.C.
MUX
11
10
01
00
AIN0
AIN31
AIN1
AIN2
A/D
Converter
MUX
2