ATXMEGA256A3B-AU Atmel, ATXMEGA256A3B-AU Datasheet - Page 17

• Manufacturer Part Number: ATXMEGA256A3B-AU
• Description: MCU AVR 256KB FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® XMEGAr

Specifications of ATXMEGA256A3B-AU

• Core Processor: AVR
• Core Size: 8/16-Bit
• Speed: 32MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 49
• Program Memory Size: 256KB (128K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.6 V ~ 3.6 V
• Data Converters: A/D 16x12b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Controller Family/series: ATXMEGA
• No. Of I/o's: 49
• Eeprom Memory Size: 4KB
• Ram Memory Size: 16KB
• Cpu Speed: 32MHz
• Rohs Compliant: Yes
• Processor Series: XMEGA
• Core: AVR
• Data Bus Width: 8 bit, 16 bit
• Data Ram Size: 16 KB
• Interface Type: SPI, TWI, USART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 49
• Number Of Timers: 7
• Operating Supply Voltage: 2.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10. System Clock and Clock options
10.1
10.2
8116I–AVR–09/10
Features
Overview
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XMEGA A3B has an advanced clock system, supporting a large number of clock sources. It
incorporates both integrated oscillators, external crystal oscillators and resonators. A high fre-
quency Phase Locked Loop (PLL) and clock prescalers can be controlled from software to
generate a wide range of clock frequencies from the clock source input.
It is possible to switch between clock sources from software during run-time. After reset the
device will always start up running from the 2 Mhz internal oscillator.
A calibration feature is available, and can be used for automatic run-time calibration of the inter-
nal 2 MHz and 32 MHz oscillators. This reduce frequency drift over voltage and temperature.
A Crystal Oscillator Failure Monitor can be enabled to issue a Non-Maskable Interrupt and
switch to internal oscillator if the external oscillator fails.
cipal clock system in XMEGA A3B.
Fast start-up time
Safe run-time clock switching
Internal Oscillators:
External clock options
PLL with internal and external clock options with 2 to 31x multiplication
Clock Prescalers with 2 to 2048x division
Fast peripheral clock running at 2 and 4 times the CPU clock speed
Automatic Run-Time Calibration of internal oscillators
Crystal Oscillator failure detection
– 32 MHz run-time calibrated RC oscillator
– 2 MHz run-time calibrated RC oscillator
– 32.768 kHz calibrated RC oscillator
– 32 kHz Ultra Low Power (ULP) oscillator
– 0.4 - 16 MHz Crystal Oscillator
– 32.768 kHz Crystal Oscillator
– External clock
Figure 10-1 on page 18
XMEGA A3B
shows the prin-
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