ATmega16U2 Atmel Corporation, ATmega16U2 Datasheet - Page 193

• Manufacturer Part Number: ATmega16U2
• Manufacturer: Atmel Corporation

Specifications of ATmega16U2

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 22
• Ext Interrupts: 21
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• 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: 2
• Output Compare Channels: 5
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

20.7
7799D–AVR–11/10
PAD suspend
Note that:
The next figures illustrates the pad behaviour:
Figure 20-11. Pad behaviour
The SUSPI flag indicated that a suspend state has been detected on the USB bus. This flag
automatically put the USB pad in Idle. The detection of a non-idle event sets the WAKEUPI flag
and wakes-up the USB pad.
• Endpoints activation:
• Endpoint disable:
• Free its memory:
• Endpoint activation:
• The data of Endpoint 0 is never lost at activation or deactivation of a higher Endpoint. The
• Deactivate and reactivate the same Endpoint with the same parameters does not lead to a
• CFGOK is set by hardware even in the case that there is a “conflict” in the memory allocation.
• In the Idle mode, the pad is put in low power consumption mode.
• In the Active mode, the pad is working.
Endpoint 0 to Endpoint 4 are configured, in the growing order. The memory of each is
reserved in the DPRAM.
The Endpoint 2 is disabled (EPEN=0), but its memory reservation is internally kept by the
controller.
The ALLOC bit is cleared: the Endpoint 3 slides down, but the Endpoint 4 does not slide.
The firmware chooses to reconfigure the Endpoint 2, but with a bigger size. The controller
reserved the memory after the endpoint 1 memory and automatically slide the Endpoint 3.
The Endpoint 4 does not move and a memory conflict appear, in that both Endpoint 3 and 4
use a common area. The data of those endpoints are potentially lost.
data is lost only if the Endpoint 0 is deactivated.
slide of the higher endpoints. For those endpoints, the data are preserved.
Idle mode
| DETACH=1
| suspend
USBE=0
& DETACH=0
& suspend
ATmega8U2/16U2/32U2
USBE=1
Active mode
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