norflash.dir

本代bootloader通过usb下载代码首先存放在sdram中

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support 
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, 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:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
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 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
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 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 */

//------------------------------------------------------------------------------
/// \dir
/// !!!Purpose
///
/// This directory provides a library of re-usable code to build %Norflash 
/// applications with Atmel AT91 microcontrollers. 
///
/// !!!Contents
/// The %norflash driver interface is implemented to support four layers of 
/// abstractions such CFI level, API level, low-level flash device driver and
/// Hardware-specific bus operations. Users can focus on writing the high-level
/// code required for their particular applications.
///
/// - CFI interface : Common Flash Memory Interface(CFI) allow in-system or 
///              programmer reading of flash device characteristics. It
///              provides basic fuction NorFlash_CFI_Detect() to detect %flash 
///              chip by CFI, it also includes some general functions to get 
///              %flash device informations like memory size, byte and word 
///              configuration, block configurations and so on.
/// - API layer: API layer consists of several functions that allow user to 
///              do operations with flash in a unified way. As a result, 
///              future device changes will not necessarily lead to the code 
///              changes in the application environments. In this %norflash 
///              library we support AMD and INTEL command set.
/// - Low-level driver: It implement procedures to program basic operations
///              described in the datasheets for flash devices. All low-level 
///              functions invkes the related supported program algorithm 
///              (AMD/Inter) which is auto detect by CFI before. The low-level 
///              code takes care of issuing the correct sequences of write/read
///              operations for each command.
/// - Hardware-specific bus operations: The low-level code requires hardware-
///             specific read/write Bus operations to communicate with the 
///             %norflash devices. The implementation of these operations is
///             hardware-platform dependent as it depends on the microprocessor
///             on the location of the memory in the microprocessor's address
///             space. 
//------------------------------------------------------------------------------