ATmega16U4 Atmel Corporation, ATmega16U4 Datasheet - Page 5
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ATmega16U4
Manufacturer Part Number
ATmega16U4
Description
Manufacturer
Atmel Corporation
Specifications of ATmega16U4
Flash (kbytes)
16 Kbytes
Pin Count
44
Max. Operating Frequency
16 MHz
Cpu
8-bit AVR
# Of Touch Channels
14
Hardware Qtouch Acquisition
No
Max I/o Pins
26
Ext Interrupts
13
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
12
Adc Resolution (bits)
10
Adc Speed (ksps)
15
Analog Comparators
1
Resistive Touch Screen
No
Temp. Sensor
Yes
Crypto Engine
No
Sram (kbytes)
2.1
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
4
Output Compare Channels
12
Input Capture Channels
2
Pwm Channels
8
32khz Rtc
No
Calibrated Rc Oscillator
Yes
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
4.3.2
4.3.2.1
Note:
4.4
7618C–AVR–07/08
Offset
Offset
15
16
17
0
1
2
3
4
5
6
7
8
1. Alternate settings can be used by an application to access additional memory segments. In this case, it is suggested that
Commands Description
DFU Configuration Descriptor
each alternate setting employ a string descriptor to indicate the target memory segment; e.g., “EEPROM”. Details concern-
ing other possible uses of alternate settings are beyond the scope of this document. However, their use is intentionally not
restricted because the authors anticipate that implements will devise additional creative uses for alternate settings.
DFU Interface Descriptor
bNumConfigurations
iSerialNumber
bInterfaceSubClass
bInterfaceProtocol
bInterfaceNumber
bAlternateSetting
iProduct
bDescriptorType
bNumEndpoints
bInterfaceClass
Field
iInterface
bLength
Field
This descriptor is identical to the standard configuration descriptor described in the USB DFU
specification version 1.0, with the exception that the bNumInterfaces field must contain the value
01h.
This is the descriptor for the only interface available when operating in DFU mode. Therefore,
the value of the bInterfaceNumber field is always zero.
Table 4-3.
The protocol implemented in the AT90USB bootloader allows to:
Overview of the protocol is detailed in
• Initiate the communication
• Program the Flash or EEPROM Data
• Read the Flash or EEPROM Data
• Program Configuration Information
• Read Configuration and Manufacturer Information
• Erase the Flash
• Start the application
Size
DFU Mode Interface Description
1
1
1
Size
1
1
1
1
1
1
1
1
1
Value
01h
0
0
Value
FEh
09h
04h
00h
00h
00h
01h
00h
00h
Index of string descriptor
Index of string descriptor
One configuration only for DFU
“Appendix-A” on page
Size of this descriptor, in bytes
INTERFACE descriptor type
Number of this interface
Alternate setting
Only the control pipe is used
Application Specific Class Code
Device Firmware Upgrade Code
The device does not use a class specific protocol on this interface
Index of the String descriptor for this interface
(1)
Description
18.
Description
5