AT90USBKEY Atmel, AT90USBKEY Datasheet - Page 8

• Manufacturer Part Number: AT90USBKEY
• Description: MCU, MPU & DSP Development Tools Demo board f/AVR MCU & AT90USB
• Manufacturer: Atmel

Specifications of AT90USBKEY

• Processor To Be Evaluated: AT90USB AVR
• Data Bus Width: 8 bit
• Interface Type: USB
• Silicon Manufacturer: Atmel
• Core Architecture: AVR
• Core Sub-architecture: AVRUSB
• Silicon Core Number: AT90USB
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AT90USBKEY2

7627A–AVR–04/06
Using the AT90USBKey
2.3
2.3.1
2.3.2
2.3.3
2-8
Reset
Power-on RESET
RESET Push Button
Main Clock XTAL
Although the AT90USB has its on-chip RESET circuitry (c.f. AT90USB Datasheet,
section “System Control and Reset), the AVRUSBKey provides to the AT90USB a
RESET signal witch can come from two different sources:
Figure 2-4 . Reset Implementation
The on-board RC network acts as power-on RESET.
By pressing the RESET push button on the AVRUSBKey, a warm RESET of the
AT90USB is performed.
To use the USB interface of the AT90USB, the clock source should always be a crystal
or external clock oscillator (the internal 8MHz RC oscillator can not be used to operate
with the USB interface). Only the following crystal frequency allows proper USB
operations: 2MHz, 4MHz, 6MHz, 8MHz, 12MHz, 16MHz. The AT90USBKey comes with
a default 8MHz crystal oscillator.
RST
VCC
R6
47k
220nF
C8
AT90USBKey Hardware User Guide
RESET