Datasheet

Table Of Contents
234
2570N–AVR–05/11
ATmega325/3250/645/6450
Table 25-5. Boundary-scan Signals for the ADC
(1)
Signal Name
Direction as seen
from the ADC Description
Recommended
Input when not
in use
Output Values when
recommended inputs are used,
and CPU is not using the ADC
COMP Output Comparator Output 0 0
ACLK Input Clock signal to differential amplifier
implemented as Switch-cap filters
00
ACTEN Input Enable path from differential amplifier to
the comparator
00
ADCBGEN Input Enable Band-gap reference as negative
input to comparator
00
ADCEN Input Power-on signal to the ADC 0 0
AMPEN Input Power-on signal to the differential amplifier 0 0
DAC_9 Input Bit 9 of digital value to DAC 1 1
DAC_8 Input Bit 8 of digital value to DAC 0 0
DAC_7 Input Bit 7 of digital value to DAC 0 0
DAC_6 Input Bit 6 of digital value to DAC 0 0
DAC_5 Input Bit 5 of digital value to DAC 0 0
DAC_4 Input Bit 4 of digital value to DAC 0 0
DAC_3 Input Bit 3 of digital value to DAC 0 0
DAC_2 Input Bit 2 of digital value to DAC 0 0
DAC_1 Input Bit 1 of digital value to DAC 0 0
DAC_0 Input Bit 0 of digital value to DAC 0 0
EXTCH Input Connect ADC channels 0 - 3 to by-pass
path around differential amplifier
11
GNDEN Input Ground the negative input to comparator
when true
00
HOLD Input Sample & Hold signal. Sample analog
signal when low. Hold signal when high. If
differential amplifier are used, this signal
must go active when ACLK is high.
11
IREFEN Input Enables Band-gap reference as AREF
signal to DAC
00
MUXEN_7 Input Input Mux bit 7 0 0
MUXEN_6 Input Input Mux bit 6 0 0
MUXEN_5 Input Input Mux bit 5 0 0
MUXEN_4 Input Input Mux bit 4 0 0
MUXEN_3 Input Input Mux bit 3 0 0
MUXEN_2 Input Input Mux bit 2 0 0
MUXEN_1 Input Input Mux bit 1 0 0
MUXEN_0 Input Input Mux bit 0 1 1