EVK525 AT90USBxxx USB Mass storage

License

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

Please read file lic_page for copyright notice.

Description

This embedded application source code illustrates how to implement a USB mass storage application with the AT90USBxxx controller on STK525 development board, using the add-on board EVK525. Please read the EVK525 User Hardware Guide before connecting the EVK525 to STK525, and before using this program. The application enumerates as a Mass Storage device containing 3 Logical Units (LUN) :

• SD/MMC interface, size depends on user's card (EVK525)
• NAND Flash device, 256 MBytes by default, but user can add others devices (EVK525). The NandFlash suppoted listing is availabled here.
• DataFlash device, 4 MBytes (STK525)

Revision

V2.0.4

USB Device:

• Fix bug about back drive voltage on D+ after VBus disconnect (USB Certification)
• Remove VBus interrupt and manage VBus state by pooling
• Fix bug during attach (the interrupt must be disable during attach to don't freeze clock)
• MassStorageClass :
  • Fix error in sense command to support Vista and Windows Seven
  • Add write Protect Management under MAC OS
  • Improve MSC compliance
  • Add MSC compliance with Linux 2.4 kernel

SD/MMC driver:

• Fix SD/MMC driver initialization

NandFlash driver:

• Add support NAND512W3A2C

V2.0.3

USB Stack

• Improve USB protocol to have a USB chap9 and MSC compliance

Fix error on DataFlash driver

Fix error on MMC/SD driver

V2.0.2

NandFlash driver :

• add feature 2xCS
• new CLE/ALE pin management to fix error on specific NF references

USB Stack:

• Move VBus interrupt to VBus pooling
• Fix USB constant about Device Status
• Add three possibilities for SN on USB : No SN, Constant SN, Unique SN

V2.0.1

NandFlash driver :

• fix major bug
• Add listing NandFlash support

USB Stack :

• Fix inquiry command
• add global define constante
• clean and fix specific request
• Fix endpoint array size
• Optimized power consumption issue in device selpowered mode: -freeze clock when ubs not connected Improvement comments

V2.0.0 and before

Don't used this package, because include a major bug on NandFlash driver. (e.g: old package "at90usb128-evk525-demo-storage-df-nf-sdmmc-1_0_0")

Architecture

As illustrated in the figure bellow, the application entry point is located is the main.c file. The main function first performs the initialization of a scheduler module and then runs it in an infinite loop. The scheduler is a simple infinite loop calling all its tasks defined in the conf_scheduler.h file. No real time schedule is performed, when a task ends, the scheduler calls the next task defined in the configuration file (conf_scheduler.h).

The application is based on two different tasks:

• The usb_task (usb_task.c associated source file), is the task performing the USB low level enumeration process in device mode or host mode.
• The storage task performs SCSI bulk only protocol decoding and performs flash memory access for device mass storage operation calling hardware specific drivers (SD/MMC, NAND Flash, DataFlash).

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