ATMEGA1281-16MU Atmel, ATMEGA1281-16MU Datasheet - Page 40

• 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. System Clock and Clock Options
9.1
9.2
9.2.1
2549M–AVR–09/10
Overview
Clock Systems and their Distribution
CPU Clock – clk
This section describes the clock options for the AVR microcontroller.
Figure 9-1
need not be active at a given time. In order to reduce power consumption, the clocks to modules
not being used can be halted by using different sleep modes, as described in
ment and Sleep Modes” on page
Figure 9-1.
The CPU clock is routed to parts of the system concerned with operation of the AVR core.
Examples of such modules are the General Purpose Register File, the Status Register and the
data memory holding the Stack Pointer. Halting the CPU clock inhibits the core from performing
general operations and calculations.
CPU
Asynchronous
Timer/Counter
Timer/Counter
Oscillator
presents the principal clock systems in the AVR and their distribution. All of the clocks
Clock Distribution
General I/O
Modules
External Clock
clk
clk
ASY
I/O
ATmega640/1280/1281/2560/2561
52. The clock systems are detailed below.
System Clock
Control Unit
AVR Clock
Multiplexer
Prescaler
Clock
ADC
Source clock
clk
Oscillator
ADC
Crystal
CPU Core
clk
clk
Reset Logic
CPU
FLASH
Crystal Oscillator
Watchdog clock
Low-frequency
Watchdog Timer
RAM
Watchdog
Oscillator
“Power Manage-
Calibrated RC
Flash and
EEPROM
Oscillator
40