ATMEGA649 Datasheet, PDF (250/375 Pages) ATMEL Corporation – 8-bit Microcontroller with In-System Programmable Flash

Scanning the Analog
Comparator
The relevant Comparator signals regarding Boundary-scan are shown in Figure 114.
The Boundary-scan cell from Figure 115 is attached to each of these signals. The sig-
nals are described in Table 110.
The Comparator need not be used for pure connectivity testing, since all analog inputs
are shared with a digital port pin as well.
Figure 114. Analog Comparator
BANDGAP
REFERENCE
ACBG
ACD
ACO
ACME
ADCEN
ADC MULTIPLEXER
OUTPUT
AC_IDLE
Figure 115. General Boundary-scan cell Used for Signals for Comparator and ADC
ShiftDR
To
Next
Cell
EXTEST
From Digital Logic/
From Analog Ciruitry
0
To Analog Circuitry/
1
To Digital Logic
0
DQ
DQ
1
G
From
Previous
Cell
ClockDR
UpdateDR
250 ATmega329/3290/649/6490
2552H–AVR–11/06