ATMEGA3250P-20AUR Atmel, ATMEGA3250P-20AUR Datasheet - Page 237

• Manufacturer Part Number: ATMEGA3250P-20AUR
• Description: MCU AVR 32K FLASH 20MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250P-20AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.5.5
8023F–AVR–07/09
Scanning the ADC
Table 23-3.
Figure 23-8
Boundary-scan cell from
used for pure connectivity testing, since all analog inputs are shared with a digital port pin as
well.
Figure 23-8. Analog to Digital Converter
The signals are described briefly in
Signal
Name
AC_IDLE
ACO
ACME
ACBG
NEGSEL_2
NEGSEL_1
NEGSEL_0
MUXEN_7
MUXEN_6
MUXEN_5
MUXEN_4
MUXEN_3
MUXEN_2
MUXEN_1
MUXEN_0
EXTCH
ADC_7
ADC_6
ADC_5
ADC_4
ADC_3
ADC_2
ADC_1
ADC_0
ADC_2
ADC_0
shows a block diagram of the ADC with all relevant control and observe signals. The
ADC_1
Direction as
Seen from the
Comparator
input
output
input
input
Boundary-scan Signals for the Analog Comparator
SCTEST
AMPEN
ACLK
ST
Figure 23-4
To Comparator
+
-
Description
Turns off Analog
Comparator when
true
Analog Comparator
Output
Uses output signal
from ADC mux when
true
Bandgap Reference
enable
1x
Table
ADCBGEN
is attached to each of these signals. The ADC need not be
VCCREN
IREFEN
AREF
23-4.
PASSEN
ACTEN
1.22V
GNDEN
ref
1.11V
ref
Recommended
Input when Not
in Use
Will become input
to µC code being
executed
ATmega325P/3250P
PRECH
DAC_9..0
ADCEN
HOLD
1
0
0
PRECH
AREF
10-bit DAC
Output Values when
Recommended Inputs
are Used
Depends upon µC code
being executed
Depends upon µC code
being executed
Depends upon µC code
being executed
AREF
+
-
DACOUT
0
COMP
COMP
237