arduino/esp8266
1
0
Fork 0
mirror of https://github.com/esp8266/Arduino.git synced 2025-07-30 16:24:09 +03:00
Code Activity

Moving sam3s peripheral library to more global sam library

Browse Source
This commit is contained in:
Thibaut VIARD
2011-06-21 00:42:25 +02:00
parent 61c55be1cb
commit 7c708132c1
107 changed files with 0 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

112
hardware/sam/system/libsam/source/crccu.c Normal file
View File

@ -0,0 +1,112 @@
/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* 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:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: 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
* 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.
* ----------------------------------------------------------------------------
*/
/** \addtogroup crccu_module Working with CRCCU
* The CRCCU driver provides the interface to configure and use the CRCCU
* peripheral.
*
* It performs a CRC computation on a Memory Area. CRC computation is performed
* from the LSB to MSB bit. Three different polynomials are available:
* CCIT802.3, CASTAGNOLI and CCIT16.
*
* To computes CRC of a buffer, the user has to follow these few steps:
* <ul>
* <li>Reset initial CRC by setting RESET bit in CRCCU_CRC_CR,</li>
* <li>Configure CRC descriptor and working mode,</li>
* <li>Start to compute CRC by setting DMAEN in CRCCU_DMA_EN,</li>
* <li>Get CRC value in CRCCU_CRC_SR.</li>
* </ul>
*
* For more accurate information, please look at the CRCCU section of the
* Datasheet.
*
* Related files :\n
* \ref crccu.c\n
* \ref crccu.h.\n
*/
/*@{*/
/*@}*/
/**
* \file
*
* Implementation of Cyclic Redundancy Check Calculation Unit (CRCCU).
*
*/
/*----------------------------------------------------------------------------
* Headers
*----------------------------------------------------------------------------*/
#include "chip.h"
/*----------------------------------------------------------------------------
* Definitions
*----------------------------------------------------------------------------*/
#define CRCCU_TIMEOUT 0xFFFFFFFF
/*----------------------------------------------------------------------------
* Exported functions
*----------------------------------------------------------------------------*/
/**
* \brief Reset initial CRC to 0xFFFFFFFF.
*/
extern void CRCCU_ResetCrcValue( Crccu* pCrccu )
{
pCrccu->CRCCU_CR = CRCCU_CR_RESET;
}
/**
* \brief Configure the CRCCU.
*
* \param dscrAddr CRC decscriptor address.
* \param mode CRC work mode
*/
extern void CRCCU_Configure( Crccu* pCrccu, uint32_t dwDscrAddr, uint32_t dwMode )
{
pCrccu->CRCCU_DSCR = dwDscrAddr ;
pCrccu->CRCCU_MR = dwMode ;
}
/**
* \brief Start to compute the CRC of a buffer.
*
* \return The CRC of the buffer.
*/
extern uint32_t CRCCU_ComputeCrc( Crccu* pCrccu )
{
uint32_t dwTimeout = 0 ;
pCrccu->CRCCU_DMA_EN = CRCCU_DMA_EN_DMAEN ;
while ( ((pCrccu->CRCCU_DMA_SR & CRCCU_DMA_SR_DMASR) == CRCCU_DMA_SR_DMASR) &&
(dwTimeout++ < CRCCU_TIMEOUT) ) ;
return (pCrccu->CRCCU_SR) ;
}