AT90USB646 Atmel Corporation, AT90USB646 Datasheet - Page 32

• Manufacturer Part Number: AT90USB646
• Manufacturer: Atmel Corporation

Specifications of AT90USB646

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 48
• Ext Interrupts: 16
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 10
• Input Capture Channels: 1
• Pwm Channels: 9
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

If a pending interrupt cannot wake the part up from the selected mode, the current consump-
tion will increase during sleep when executing the SLEEP instruction directly after a SEI
instruction.
Problem Fix/workaround
Before entering sleep, interrupts not used to wake up the part from the sleep mode should
be disabled.
1. Asynchronous timer interrupt wake up from sleep generates multiple interrupts
If the CPU core is in sleep and wakes-up from an asynchronous timer interrupt and then go
back in sleep mode again it may wake up several times.
Problem Fix/workaround
A s o f t w a r e w o r k a r o u n d i s t o w a i t w i t h p e r f o r m i n g t h e s l e e p i n s t r u c t i o n u n t i l
TCNT2>OCR2+1.
AT90USB64/128
32
7593KS–AVR–11/09