ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 18

• Manufacturer Part Number: ATmega32U4
• 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

8. Bootloader History
9. Appendix-A
18
The following table shows the different bootloader revision and associated changes.
Table 8-1.
Table 9-1.
Id_prog_start
01h
Id_display_data
03h
Id_write_command
04h
Id_read_command
05h
Id_change _base
_address
06h
Command Identifier
AT90USB1287
AT90USB1286
AT90USB647
AT90USB646
AT90USB162
ATmega32U4
ATmega16U4
AT90USB82
Product
USB Bootloader History
Summary of Frames from Host
data[0]
Bootloader Revision
00h
01h
03h
00h
01h
00h
01h
02h
00h
03h
1.0.1
1.0.0
1.0.1
1.0.5
1.0.0
00h
01h
02h
30h
31h
60h
61h
00
data[1]
FFh
00h
01h
start_address
start_address
“PP”
data[2]
address
Allow to use 16MHz cristal with 3.3V power supply and
data[3]
end_address
end_address
Improved USB autobaud process
data[4]
Initial Revision
Initial Revision
Initial Revision
CKDIV8 fuse.
Changes
Init FLASH programming
Init EEPROM programming
Display FLASH Data
Blank Check in FLASH
Display EEPROM Data
Full chip Erase (bits at FFh)
Hardware reset
LJMP address
Read Bootloader Version
Read Device boot ID1
Read Device boot ID2
Read Manufacturer Code
Read Family Code
Read Product Name
Read Product Revision
Select “PP” 64kBytes flash
page number
Description
7618C–AVR–07/08