ATMEGA16U4-AU Atmel, ATMEGA16U4-AU Datasheet - Page 263

• 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

21.12 Registers description
21.12.1
7766F–AVR–11/10
USB general registers
Figure 21-13. Plug-in Detection Input Block Diagram
The control logic of the VBUS pad outputs a signal regarding the VBUS voltage level:
• 7-1 – Reserved
These bits are reserved. Do not modify these bits.
• 0 – UVREGE: USB pad regulator Enable
Set to enable the USB pad regulator. Clear to disable the USB pad regulator.
• 7 – USBE: USB macro Enable Bit
Set to enable the USB controller. Clear to disable and reset the USB controller, to disable the
USB transceiver and to disable the USB controller clock inputs.
• 6 – Reserved
The value read from these bits is always 0. Do not set these bits.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
• The “Session_valid” signal is active high when the voltage on the UVBUS pad is higher or
• The VBUS status bit is set when “Session_valid” signal is active (VBUS > 1.4V).
• The VBUSTI flag is set each time the VBUS state changes.
• The USB peripheral cannot attach to the bus while VBUS bit is not set.
equal to 1.4V. If lower than 1.4V, the signal is not active.
VBUS
USBE
R/W
R/W
7
0
7
0
-
R/W
R/W
0
6
-
6
0
-
Pad logic
FRZCLK
R/W
VDD
VSS
R
5
0
5
1
-
OTGPADE
R/W
Session_valid
R/W
4
0
-
4
0
R
3
0
-
R
3
0
-
USBSTA.0
VBUS
R
2
0
-
R
2
0
-
R
R/W
1
0
ATmega16/32U4
-
1
0
-
UVREGE
VBUSTE
R/W
R/W
0
0
0
0
VBUSTI
USBINT.0
UHWCON
USBCON
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