AVR32 USB Software Framework for Dual-Role Devices

License

Use of this program is subject to Atmel's End User License Agreement.

Please read the Copyright Notice at the bottom of this page.

Description

This embedded application source code illustrates how to implement a USB interfaced application on the AVR32 microcontroller.

As the AVR32 implements a device/host USB controller, the embedded application can operate in one of the following USB operating modes:

To optimize embedded code/RAM size and reduce the number of source modules, the application can be configured to use one and only one of these operating modes.

About the Sample Application

By default the sample code is delivered with a simple preconfigured dual-role USB application. It means that the code generated allows to operate as a device or a host depending on the USB ID pin:

appli.jpg

Application Overview

Thus two instances of this application can be connected together with a mini-A - mini-B cable.

Note:
  • When an EVK1101/UC3C-EK/EVK1104/EVK1105 is the host device, LED2 and LED3 will quickly blink. LED0 & LED1 will slowly blink with the following pattern: LED0 on/LED1 off, then LED0 off/LED1 on, then LED0 on/LED1 on.
  • When an EVK1100 is the host device, LED4(red light of the led tagged as LED5 on the PCB) will quickly blink. LED0, LED1, LED2 and LED3 will slowly blink in a complex pattern.
  • The host device may display the following messages on USART1(EVK1100/EVK1101)/USART0-CDC(EVK1105)/USART1-CDC(EVK1104)/USART2-CDC(UC3C-EK) depending on the current USB events: "Device connected", "Unsupported device", "Device enumerated", "USB suspended", "USB resumed". While the slave device never displays any message on USART.

Architecture

As illustrated in the figure below, the application entry point is located in the enum_example.c file. The main function first performs the initialization of services and tasks and then runs them in an infinite loop.

The sample dual-role application is based on three different tasks:

arch_full.jpg

Architecture Overview

Configuration

The sample application is configured to implement both host and device functionalities. Of course it can also be configured to be used only in device or reduced-host mode (see the conf_usb.h file). Depending on the USB operating mode selected, the USB task will call either the USB host task (usb_host_task.c), or the USB device task (usb_device_task.c) to manage USB specification chapter 9 requests.

Note:
The B-device descriptors used for this sample application are not directly usable for enumeration with a standard PC host system. Please see Contact Information for real device application examples (mass storage, HID mouse, HID keyboard, CDC, etc.).

Contact Information

For further information, visit Atmel AVR32.
Support and FAQ: http://support.atmel.no/

Copyright Notice

Copyright (c) 2009 Atmel Corporation. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. The name of Atmel may not be used to endorse or promote products derived from this software without specific prior written permission.

4. This software may only be redistributed and used in connection with an Atmel AVR product.

THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE


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