AT90USB646 datasheet(285/456 Pages) ATMEL

Part #	AT90USB646

Description	8-bit Atmel Microcontroller with 64/128Kbytes of ISP Flash and USB Controller

PDF	456 Pages

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Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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285 / 456 page

285

7593L–AVR–09/12

AT90USB64/128

24. USB host operating modes

This mode is available only on Atmel AT90USB647/1287 products.

24.1

Pipe description

For the USB Host controller, the term of Pipe is used instead of Endpoint for the USB Device

controller. A Host Pipe corresponds to a Device Endpoint, as described in the USB specification.

Figure 24-1. Pipes and endpoints in a USB system.

In the USB Host controller, a Pipe will be associated to a Device Endpoint, considering the

Device Configuration Descriptors.

24.2

Detach

The reset value of the DETACH bit is 1. Thus, the firmware has the responsibility of clearing this

bit before switching to the Host mode (HOST set).

24.3

Power-on and reset

Figure 24-2 explains the USB host controller main states on power-on.

Figure 24-2. USB host controller states after reset.

Host

Ready

Host

Idle

Device

disconnection

<any

other

state>

Device

connection

Clock stopped

Macro off

Device

disconnection

Host

Suspend

SOFE=1

SOFE=0

AT90USB646 Datasheet(PDF) 285 Page - ATMEL Corporation