ATMEGA16U2-16AU Atmel, ATMEGA16U2-16AU Datasheet - Page 189

• Manufacturer Part Number: ATMEGA16U2-16AU
• Description: 8-bit Microcontrollers - MCU 16K Flash
• Manufacturer: Atmel

Specifications of ATMEGA16U2-16AU

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: AVR
• Data Bus Width: 8 bit
• Program Memory Size: 16 KB
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Program Memory Type: Flash
• Factory Pack Quantity: 1250

20.3.3
20.4
20.4.1
20.4.2
7799D–AVR–11/10
General Operating Modes
Design guidelines
Introduction
Power-on and reset
The following design guidelines should be met:
In addition it is highly recommended to connect a 10μF capacitor to the VBUS line
The USB controller is disabled and reset after a hardware reset generated by:
In the case of USB End Of Reset (EOR), the USB controller is reset, but not disabled. Therefore
the device remains attached.
Figure 20-7 on page 189
Figure 20-7. USB controller states after reset
• Serial resistors on USB Data lines must have 22 Ohms value (
• Traces from the input USB receptacle (or from the cable connection in the case of a tethered
• Voltage transient / ESD suppressors may also be used to prevent USB pads to be damaged
• U
device) to the USB microcontroller pads should be as short as possible, and follow differential
traces routing rules (same length, as near as possible and avoid vias accumulation).
by external disturbances.
cap
– Power on reset
– External reset
– Watchdog reset
– Brown out reset
– debugWIRE reset
– USB End Of Reset
capacitor should be 1μF (
Clock stopped
FRZCLK = 1
(macro off)
USBE = 1
Device
illustrates the USB controller main states on power-on:
+/-
10%) for correct operation.
USBE = 0
Reset
HW RESET
(from EOR)
ATmega8U2/16U2/32U2
USBE = 0
USBE = 0
+/-
(except from EOR)
Any other
5%).
HW RESET
state
189