ATMEGA1281-16MU Atmel, ATMEGA1281-16MU Datasheet - Page 46

• Manufacturer Part Number: ATMEGA1281-16MU
• Description: IC MCU AVR 128K FLASH 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA1281-16MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 8K 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: 64-MLF®, 64-QFN
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: 2-Wire, SPI, UART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 6
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRRZ541, ATAVRRAVEN, ATAVRRZRAVEN, ATAVRRZUSBSTICK, ATAVRISP2, ATAVRRZ201
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 channel
• For Use With: ATSTK600-TQFP64 - STK600 SOCKET/ADAPTER 64-TQFPATAVRDB101 - MODULE DISPLAY LCD/RGB BACKLIGHT770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.7
2549M–AVR–09/10
Calibrated Internal RC Oscillator
The capacitance (Ce + Ci) needed at each XTAL/TOSC pin can be calculated by using:
where:
Ce - is optional external capacitors as described in
Ci - is is the pin capacitance in
CL - is the load capacitance for a 32.768 kHz crystal specified by the crystal vendor.
C
Crystals specifying load capacitance (CL) higher than the ones given in the
45, require external capacitors applied as described in
Figure 9-3.
To find suitable load capacitance for a 32.768 kHz crysal, please consult the crystal datasheet.
When this oscillator is selected, start-up times are determined by the SUT Fuses and CKSEL0
as shown in
Table 9-8.
Note:
By default, the Internal RC Oscillator provides an approximate 8 MHz clock. Though voltage and
temperature dependent, this clock can be very accurately calibrated by the user. See
on page 371
with the CKDIV8 Fuse programmed. See
S
- is the total stray capacitance for one XTAL/TOSC pin.
Slowly rising power
Slowly rising power
Power Conditions
Fast rising power
Fast rising power
BOD enabled
BOD enabled
1. These options should only be used if frequency stability at start-up is not important for the
application.
Table
and
Crystal Oscillator Connections
Start-up Times for the Low Frequency Crystal Oscillator Clock Selection
“Internal Oscillator Speed” on page 403
9-8.
Start-up Time from
Power-down and
Table 9-7 on page
Reserved
Reserved
ATmega640/1280/1281/2560/2561
Power-save
32K CK
32K CK
32K CK
1K CK
1K CK
1K CK
Ce
+
“System Clock Prescaler” on page 49
Ci
=
2 CL
⋅
45.
Figure 9-2 on page
–
Additional Delay
14CK + 4.1 ms
14CK + 65 ms
Figure 9-2 on page
14CK + 4.1 ms
14CK + 65 ms
C
(V
from Reset
s
for more details. The device is shipped
CC
14CK
14CK
= 5.0V)
(1)
(1)
(1)
43.
43.
CKSEL0
Table 9-7 on page
0
0
0
0
1
1
1
1
for more details.
Table 30-1
SUT1:0
00
01
10
11
00
01
10
11
46