ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 241

• Manufacturer Part Number: ATMEGA169
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Scanning the ADC
2514P–AVR–07/06
Table 104. Boundary-scan Signals for the Analog Comparator
Figure 115 shows a block diagram of the ADC with all relevant control and observe sig-
nals. The Boundary-scan cell from Figure 111 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 115. Analog to Digital Converter
The signals are described briefly in Table 105.
NEGSEL_2
NEGSEL_1
NEGSEL_0
MUXEN_7
MUXEN_6
MUXEN_5
MUXEN_4
MUXEN_3
MUXEN_2
MUXEN_1
MUXEN_0
Signal
Name
AC_IDLE
ACO
ACME
ACBG
EXTCH
ADC_7
ADC_6
ADC_5
ADC_4
ADC_3
ADC_2
ADC_1
ADC_0
ADC_2
ADC_1
ADC_0
Direction as
Seen from the
Comparator
input
output
input
input
SCTEST
AMPEN
ACLK
ST
To Comparator
+
-
1x
Description
Turns off Analog
Comparator when
true
Analog
Comparator Output
Uses output signal
from ADC mux
when true
Bandgap
Reference enable
ADCBGEN
VCCREN
IREFEN
AREF
PASSEN
ACTEN
1.22V
GNDEN
ref
1.11V
ref
Recommended
Input when Not
in Use
1
Will become
input to µC code
being executed
0
0
PRECH
DAC_9..0
ADCEN
HOLD
ATmega169/V
PRECH
AREF
10-bit DAC
Output Values when
Recommended
Inputs are Used
Depends upon µC
code being executed
0
Depends upon µC
code being executed
Depends upon µC
code being executed
AREF
+
-
DACOUT
COMP
COMP
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