AT32UC3L0256 Atmel Corporation, AT32UC3L0256 Datasheet - Page 271

• Manufacturer Part Number: AT32UC3L0256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3L0256

• Flash (kbytes): 256 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 50 MHz
• Cpu: 32-bit AVR
• # Of Touch Channels: 17
• Hardware Qtouch Acquisition: Yes
• Max I/o Pins: 36
• Ext Interrupts: 36
• Usb Speed: No
• Usb Interface: No
• Spi: 5
• Twi (i2c): 2
• Uart: 4
• Lin: 4
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 460
• Analog Comparators: 8
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 16
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.62 to 3.6
• Operating Voltage (vcc): 1.62 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 18
• Input Capture Channels: 12
• Pwm Channels: 35
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

14.5.8
32145A–12/2011
Synchronization
If ADD is ‘1’, the prescaler frequency is increased:
Note that for these formulas to be within an error of 0.01%, it is recommended that the prescaler
bit that is used as the clock for the counter (selected by CR.PSEL) or to trigger the periodic inter-
rupt (selected by PIRn.INSEL) be bit 6 or higher.
As the prescaler and counter operate asynchronously from the user interface, the AST needs a
few clock cycles to synchronize the values written to the CR, CV, SCR, WER, EVE, EVD, PIRn,
ARn, and DTR registers. The Busy bit in the Status Register (SR.BUSY) indicates that the syn-
chronization is ongoing. During this time, writes to these registers will be discarded and reading
will return a zero value.
Note that synchronization takes place also if the prescaler is clocked from CLK_AST.
f
TUNED
=
f
0
⎛
⎜
⎜
⎜
⎝
1
+
------------------------------------------------------------------------------- -
roundup
⎛
⎝
AT32UC3L0128/256
------------------- -
VALUE
256
1
⎞
⎠
2
EXP
–
1
⎞
⎟
⎟
⎟
⎠
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