ATMEGA16U4-AU Atmel, ATMEGA16U4-AU Datasheet - Page 26

• Manufacturer Part Number: ATMEGA16U4-AU
• Description: MCU AVR 16K FLASH USB 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16U4-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 26
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ATMEGA16x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1.25 KB
• Interface Type: SPI, TWI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 26
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 12 Channel
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5.4
5.4.1
5.4.2
5.4.3
5.4.4
7766F–AVR–11/10
I/O Memory
General Purpose I/O Registers
General Purpose I/O Register 2 – GPIOR2
General Purpose I/O Register 1 – GPIOR1
General Purpose I/O Register 0 – GPIOR0
The I/O space definition of the ATmega16U4/ATmega32U4 is shown in
page
All ATmega16U4/ATmega32U4 I/Os and peripherals are placed in the I/O space. All I/O loca-
tions may be accessed by the LD/LDS/LDD and ST/STS/STD instructions, transferring data
between the 32 general purpose working registers and the I/O space. I/O Registers within the
address range 0x00 - 0x1F are directly bit-accessible using the SBI and CBI instructions. In
these registers, the value of single bits can be checked by using the SBIS and SBIC instructions.
Refer to the instruction set section for more details. When using the I/O specific commands IN
and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing I/O Registers as data
space using LD and ST instructions, 0x20 must be added to these addresses. The
ATmega16U4/ATmega32U4 is a complex microcontroller with more peripheral units than can be
supported within the 64 location reserved in Opcode for the IN and OUT instructions. For the
Extended I/O space from 0x60 - 0xFF in SRAM, only the ST/STS/STD and LD/LDS/LDD instruc-
tions can be used.
For compatibility with future devices, reserved bits should be written to zero if accessed.
Reserved I/O memory addresses should never be written.
Some of the Status Flags are cleared by writing a logical one to them. Note that, unlike most
other AVRs, the CBI and SBI instructions will only operate on the specified bit, and can therefore
be used on registers containing such Status Flags. The CBI and SBI instructions work with reg-
isters 0x00 to 0x1F only.
The I/O and peripherals control registers are explained in later sections.
The ATmega16U4/ATmega32U4 contains three General Purpose I/O Registers. These registers
can be used for storing any information, and they are particularly useful for storing global vari-
ables and Status Flags. General Purpose I/O Registers within the address range 0x00 - 0x1F
are directly bit-accessible using the SBI, CBI, SBIS, and SBIC instructions.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
408.
7
MSB
R/W
0
7
MSB
R/W
0
7
MSB
R/W
0
6
R/W
0
6
R/W
0
6
R/W
0
5
R/W
0
5
R/W
0
5
R/W
0
4
R/W
0
4
R/W
0
4
R/W
0
3
0
3
0
3
0
R/W
R/W
R/W
2
R/W
0
2
R/W
0
2
R/W
0
1
R/W
0
1
R/W
0
1
R/W
0
ATmega16/32U4
0
LSB
R/W
0
0
LSB
R/W
0
0
LSB
R/W
0
“Register Summary” on
GPIOR2
GPIOR1
GPIOR0
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