AT90USB646 datasheet(297/434 Pages) ATMEL

Part #	AT90USB646

Description	Microcontroller with 64/128K Bytes of ISP Flash and USB Controller

PDF	434 Pages

Scroll/Zoom	100%

Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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297 / 434 page

297

7593A–AVR–02/06

AT90USB64/128

23.12 Control Pipe management

A Control transaction is composed of 3 phases:

• SETUP

• Data (IN or OUT)

• Status (OUT or IN)

The firmware has to change the Token for each phase.

The initial data toggle is set for the corresponding token (ONLY for Control Pipe):

• SETUP: Data0

• OUT: Data1

• IN: Data1 (expected data toggle)

23.13 OUT Pipe management

The Pipe must be configured and not frozen first.

Note: if the firmware decides to switch to suspend mode (clear SOFEN) even if a bank is ready

to be sent, the USB controller will automatically exit from Suspend mode and the bank will be

sent.

The TXOUT bit is set by hardware when the current bank becomes free. This triggers an inter-

rupt if the TXOUTE bit is set. The FIFOCON bit is set at the same time. The CPU writes into the

FIFO and clears the FIFOCON bit to allow the USB controller to send the data.

AT90USB646 Datasheet(PDF) 297 Page - ATMEL Corporation