AT90USB82 datasheet(36/306 Pages) ATMEL

номер детали	AT90USB82

подробное описание детали	8-bit Microcontroller with 8/16K Bytes of ISP Flash and USB Controller

PDF	306 Pages

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производитель	ATMEL [ATMEL Corporation]

домашняя страница	http://www.atmel.com

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7707E–AVR–11/08

AT90USB82/162

“0011”, giving a division factor of 8 at start up. This feature should be used if the selected clock

source has a higher frequency than the maximum frequency of the device at the present operat-

ing conditions. Note that any value can be written to the CLKPS bits regardless of the CKDIV8

Fuse setting. The Application software must ensure that a sufficient division factor is chosen if

the selected clock source has a higher frequency than the maximum frequency of the device at

the present operating conditions. The device is shipped with the CKDIV8 Fuse programmed.

6.9

PLL

The PLL is used to generate internal high frequency (48 MHz) clock for USB interface, the PLL

input is generated from an external low-frequency (the crystal oscillator or external clock input

pin from XTAL1).

6.9.1

Internal PLL for USB interface

The internal PLL in AT90USB82/162 generates a clock frequency that is 6x multiplied from nom-

inally 8 MHz input. The source of the 8 MHz PLL input clock is the output of the internal PLL

clock prescaler that generates the 8 MHz.

Table 6-9.

Clock Prescaler Select

CLKPS3

CLKPS2

CLKPS1

CLKPS0

Clock Division Factor

128

256

Reserved

AT90USB82 датащи(PDF) 36 Page - ATMEL Corporation