ATxmega256A3U Atmel Corporation, ATxmega256A3U Datasheet - Page 76

• Manufacturer Part Number: ATxmega256A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega256A3U

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

35.14.6
Table 35-20. External 32.768kHz Crystal Oscillator and TOSC characteristics
Note:
35.14.7
8386A–AVR–07/11
Symbol
ESR/R1
C
IN_TOSC
1. See
External 32.768kHz Crystal Oscillator and TOSC characteristics
External Clock Characteristics
Parameter
Recommended crystal equivalent
series resistance (ESR)
Input capacitance between TOSC pins
Recommended Safety factor
Figure 35-2 on page 76
Figure 35-2. TOSC input capacitance
The input capacitance between the TOSC pins is C
when oscillating without external capacitors.
Figure 35-3. External Clock Drive Waveform
V
IL1
for definition
V
IH1
t
CH
T
O
Crystal load capacitance 6.5pF
Crystal load capacitance 9.0pF
Normal mode
Low power mode
capacitance load matched to
crystal specification
S
C
1
Condition
32.768 KHz crystal
Device internal
C
L1
External
t
CL
t
CR
C
L1
L2
+ C
L2
Min
3
t
in series as seen from the crystal
CK
T
O
Typ
S
1.7
2.2
C
XMEGA A3U
t
CH
2
Max
60
35
Units
kΩ
pF
t
76
CF