ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 13
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ATmega32U4
Manufacturer Part Number
ATmega32U4
Description
Manufacturer
Atmel Corporation
Specifications of ATmega32U4
Flash (kbytes)
32 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)
3.3
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
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
Company:
Part Number:
ATmega32U4-16AU
Manufacturer:
MAXIM
Quantity:
1 000
Company:
Part Number:
ATmega32U4-AU
Manufacturer:
FREESCALE
Quantity:
125
Company:
Part Number:
ATmega32U4-MUR
Manufacturer:
UCC
Quantity:
1 001
Part Number:
ATmega32U4RC-MU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
4.9
4.9.1
4.9.2
4.10
7618C–AVR–07/08
Erasing the Flash
Starting the Application
Request from Host
Answers from Bootloader
The flow described below allows the user to erase the Flash memory.
The Full Chip erase command erases the whole Flash.
To start the erasing operation, the Host sends a DFU_DNLOAD request with a Write Command
in the data field (2 bytes).
The device has two possible answers to a DFU_GETSTATUS request:
The flow described below allows to start the application directly from the bootloader upon a spe-
cific command reception.
Two options are possible:
•
•
To start the application, the Host sends a DFU_DNLOAD request with the specified application
start type in the data field (3 or 5 bytes).
This request is immediately followed by a second DFU_DNLOAD request with no data field to
start the application with one of the 2 options.
Command Identifier
• If the chip is protected from program access, an “err_WRITE” status is returned to the Host.
• Otherwise, the device status is “OK“.
Id_write_command
Start the application with an internal hardware reset using watchdog.
When the device receives this command the watchdog is enabled and the bootloader enters
a waiting loop until the watchdog resets the device.
Start the application without reset.
A jump at the address 0000h is used to start the application without reset.
04h
data[0]
00h
SETUP
IN
OUT
data[1]
FFh
data[2]
Byte value (1 byte)
DFU_UPLOAD
ZLP
data[3]
data[4]
Full chip Erase (bits at FFh)
Description
13