A000047 Arduino, A000047 Datasheet - Page 48

• Manufacturer Part Number: A000047
• Description: MCU, MPU & DSP Development Tools Mega2560
• Manufacturer: Arduino
• Series: -r
• Type: MCUr

Specifications of A000047

• Processor To Be Evaluated: ATmega2560
• Interface Type: USB, I2C, SPI
• Dimensions: 4 in x 2.1 in
• Operating Supply Voltage: 5 V
• Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ATmega2560

9.9
2549M–AVR–09/10
External Clock
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 9-12.
To drive the device from an external clock source, XTAL1 should be driven as shown in
9-4. To run the device on an external clock, the CKSEL Fuses must be programmed to “0000”.
Figure 9-4.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table 9-15 on page
Table 9-13.
Table 9-14.
When applying an external clock, it is required to avoid sudden changes in the applied clock fre-
quency to ensure stable operation of the MCU. A variation in frequency of more than 2% from
one clock cycle to the next can lead to unpredictable behavior. If changes of more than 2% is
required, ensure that the MCU is kept in Reset during the changes.
Slowly rising power
Slowly rising power
Power Conditions
Power Conditions
Fast rising power
Fast rising power
9-12.
BOD enabled
BOD enabled
Start-up Times for the 128 kHz Internal Oscillator
External Clock Drive Configuration
Crystal Oscillator Clock Frequency
Start-up Times for the External Clock Selection
Nominal Frequency
51.
0 - 16 MHz
EXTERNAL
Start-up Time from Power-
Start-up Time from Power-
SIGNAL
CLOCK
down and Power-save
down and Power-save
ATmega640/1280/1281/2560/2561
NC
Reserved
Reserved
6 CK
6 CK
6 CK
6 CK
6 CK
6 CK
XTAL2
XTAL1
GND
Additional Delay from
Additional Delay from
Reset (V
14CK + 4.1 ms
14CK + 64 ms
14CK + 65 ms
14CK + 4 ms
Reset
14CK
14CK
CC
CKSEL3:0
= 5.0V)
0000
SUT1:0
SUT1:0
00
01
10
11
Figure
00
01
10
11
48