ATMEGA16U4-AU Atmel, ATMEGA16U4-AU Datasheet - Page 266

• 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

22. USB Device Operating modes
22.1
22.2
22.3
7766F–AVR–11/10
Introduction
Power-on and reset
Endpoint reset
The USB device controller supports full speed and low speed data transfers. In addition to the
default control endpoint, it provides six other endpoints, which can be configured in control, bulk,
interrupt or isochronous modes:
The controller starts in the “idle” mode. In this mode, the pad consumption is reduced to the
minimum.
The next diagram explains the USB device controller main states on power-on:
Figure 22-1. USB device controller states after reset
The reset state of the Device controller is:
The D+ or D- pull-up will be activated as soon as the DETACH bit is cleared and VBUS is
present.
The macro is in the ‘Idle’ state after reset with a minimum power consumption and does not
need to have the PLL activated to enter this state.
The USB device controller can at any time be reset by clearing USBE (disable USB interface).
An endpoint can be reset at any time by setting in the UERST register the bit corresponding to
the endpoint (EPRSTx). This resets:
• Endpoint 0:programmable size FIFO up to 64 bytes, default control endpoint
• Endpoints 1 programmable size FIFO up to 256 bytes in ping-pong mode.
• Endpoints 2 to 6: programmable size FIFO up to 64 bytes in ping-pong mode.
• the macro clock is stopped in order to minimize the power consumption (FRZCLK set),
• the USB device controller internal state is reset (all the registers are reset to their default
• the endpoint banks are reset
• the D+ or D- pull up are not activated (mode Detach)
• the internal state machine on that endpoint,
• the Rx and Tx banks are cleared and their internal pointers are restored,
value. Note that DETACH is set.)
RESET
HW
USBE=0
Reset
USBE=0
state>
<any
other
USBE=1
Idle
ATmega16/32U4
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