At90Usb1287 Avr Microcontroller; Serial Links - Atmel AT88CK109STK3 Hardware User's Manual

AT88SCK109STK3

AT90USB1287 AVR Microcontroller

3.4

Serial Links

3.5
USB
3.5.1
USART
3.5.2
SPI / TWI Selector Switch
3.5.3
3-8
8699A—CRYPTO—10/09
Downloaded from Elcodis.com electronic components distributor
To use the USB interface of the AT90USB1287, the clock source should always be a crystal or an
external clock oscillator (the internal 8MHz RC oscillator cannot be used to operate the USB
interface). Only the following crystal frequencies allow proper USB operations: 2MHz, 4MHz,
6MHz, 8MHz, 12MHz, and 16MHz. The AT88Microbase comes with a default 16MHz crystal
oscillator, which is required
CryptoAuthentication communication.
The AT88Microbase is supplied with a standard USB Type-A receptacle. The AT88Microbase only
operates as an "USB device".
USB Type-A Receptacle
Figure 6.
The AT90USB1287 AVR comes with an on-chip USART peripheral (USART1).
asynchronous mode is supported. See section 3.6.3 for pinout details.
The SPI – TWI selector switch (K1) allows either the SPI pins (MOSI and SCLK) or the TWI pins
(SDA and SCL) to be routed to the 10 pin Interface header, J1. See section 3.6.3 for pinout details.
TWI – SPI Selector Switch
Figure 7.
to obtain the 230.4K USART baud rate needed
AT88CK109STK3 User Guide
for
Only the