ATXMEGA256A3B-MH Atmel, ATXMEGA256A3B-MH Datasheet - Page 77

• Manufacturer Part Number: ATXMEGA256A3B-MH
• Description: MCU AVR 256KB FLASH A3B 64-QFN
• Manufacturer: Atmel
• Series: AVR® XMEGAr

Specifications of ATXMEGA256A3B-MH

• 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-MLF®, 64-QFN
• Processor Series: ATXMEGA256x
• Core: AVR8
• Data Bus Width: 8 bit, 16 bit
• Data Ram Size: 16 KB
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 49
• Number Of Timers: 7
• Operating Supply Voltage: 1.6 V to 3.6 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
• On-chip Adc: 12 bit, 8 Channel
• On-chip Dac: 12 bit, 2 Channel
• For Use With: ATAVRONEKIT - KIT AVR/AVR32 DEBUGGER/PROGRMMRATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATXMEGA256A3B-MU; ATXMEGA256A3B-MU

Figure 7-1.
7.3
7.3.1
7.3.2
8077H–AVR–12/09
Clock Distribution
System Clock - clk
CPU Clock - clk
Brown-out
Detection
The Clock system, clock sources and clock distribution
Real Time
Counter
Figure 7-1 on page 77
The System Clock is the output from the main system clock selection. This is fed into the pres-
calers that are used to generate all internal clocks except the Asynchronous Clock.
The CPU Clock is routed to the CPU and Non-Volatile Memory. Halting the CPU Clock inhibits
the CPU from executing instructions.
Watchdog
CPU
Int. ULP
32 kHz
Timer
SYS
clk
rtc
32.768 kHz
Int. Osc.
Peripherals
clk
PER4
clk
PER2
clk
presents the principal clock distribution in the XMEGA.
PER
Int. Osc.
2 MHz
RAM
System Clock
System Clock Multiplexer
Prescalers
clk
SYS
Int. Osc.
32 MHz
PLL
32 kHz
XTAL
AVR CPU
clk
CPU
0.4-16 Mhz
XTAL
Non-Volatile
Memory
XMEGA A
External
Clock
77