ATmega32U2 Atmel Corporation, ATmega32U2 Datasheet - Page 3
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ATmega32U2
Manufacturer Part Number
ATmega32U2
Description
Manufacturer
Atmel Corporation
Specifications of ATmega32U2
Flash (kbytes)
32 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
20
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)
1
Eeprom (bytes)
1024
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
4. Protocol
4.1
7618C–AVR–07/08
Device Firmware Upgrade Introduction
These different conditions are summarized in
Figure 3-1.
Device Firmware Upgrade (DFU) is the mechanism implemented to perform device firmware
modifications. Any USB device can exploit this capability by supporting the requirements speci-
fied in this document.
Because it is unpractical for a device to concurrently perform both DFU operations and its nor-
mal run-time activities, these normal activities must cease for the duration of the DFU
operations. Doing so means that the device must change its operating mode; i.e., a printer is not
a printer while it is undergoing a firmware upgrade; it is a PROM programmer. However, a
• Boot Reset Fuse The Boot Reset Fuse (BOOTRST) can be programmed so that the Reset
• External Hardware conditions The Hardware Boot Enable fuse (HWBE) can be
Vector points to the Boot Flash section start address after reset. Once the user code is
loaded, a bootloader command (“start application”) can start executing the application code.
Note that the fuses cannot be changed by the MCU itself. This means that once the Boot
Reset Fuse is programmed, the Reset Vector will always point to the Bootloader Reset and
the fuse can only be changed through the serial or parallel programming interface. The
BOOTRST fuse is not active in the default factory configuration.
programmed so that upon special hardware conditions under reset, the bootloader execution
is forced after reset.
Boot Process
Start Bootloader
PC = boot loader section
Yes
Yes
"Software activation (jump)"
Figure 3-1 on page
BOOTRST = 0
Ext Hardware
conditions
Reset
No
No
PC = 0000h
Application
Running
3.
3