Datasheet

265
2490R–AVR–02/2013
ATmega64(L)
Scanning the ADC Figure 134 shows a block diagram of the ADC with all relevant control and observe signals. The
Boundary-scan cell from Figure 130 is attached to each of these signals. The ADC need not be
used for pure connectivity testing, since all analog inputs are shared with a digital port pin as
well.
Figure 134. Analog to Digital Converter
The signals are described briefly in Table 104.
10-bit DAC
+
-
AREF
PRECH
DACOUT
MUXEN_7
ADC_7
MUXEN_6
ADC_6
MUXEN_5
ADC_5
MUXEN_4
ADC_4
MUXEN_3
ADC_3
MUXEN_2
ADC_2
MUXEN_1
ADC_1
MUXEN_0
ADC_0
NEGSEL_2
ADC_2
NEGSEL_1
ADC_1
NEGSEL_0
ADC_0
EXTCH
+
-
+
-
10x
20x
G10 G20
ST
ACLK
AMPEN
2.56V
Ref
IREFEN
AREF
VCCREN
DAC_9..0
ADCEN
HOLD
GNDEN
PASSEN
ACTEN
COMP
SCTEST
ADCBGEN
TO COMPARATOR
1.22V
Ref
AREF