crc.cpp

00001 /*****************************************************************************
00002  *
00003  *   Copyright(C) 2011, Embedded Artists AB
00004  *   All rights reserved.
00005  *
00006  ******************************************************************************
00007  * Software that is described herein is for illustrative purposes only
00008  * which provides customers with programming information regarding the
00009  * products. This software is supplied "AS IS" without any warranties.
00010  * Embedded Artists AB assumes no responsibility or liability for the
00011  * use of the software, conveys no license or title under any patent,
00012  * copyright, or mask work right to the product. Embedded Artists AB
00013  * reserves the right to make changes in the software without
00014  * notification. Embedded Artists AB also make no representation or
00015  * warranty that such application will be suitable for the specified
00016  * use without further testing or modification.
00017  *****************************************************************************/
00018 
00019 
00020 
00021 /******************************************************************************
00022  * Includes
00023  *****************************************************************************/
00024 
00025 #include "mbed.h"
00026 #include "crc.h"
00027 
00028 
00029 /******************************************************************************
00030  * Defines and typedefs
00031  *****************************************************************************/
00032 
00033 #define NUM_CRC_BUFF_ENTRIES  (100)
00034 
00035 #define CRC32_INIT()  do { LPC_CRC->MODE = 0x00000036; LPC_CRC->SEED = 0xffffffff; } while(0)
00036 
00037 #define CRC32_WRITE8(__val)   LPC_CRC->WR_DATA_BYTE.DATA = (uint8_t)(__val)
00038 #define CRC32_WRITE16(__val)  LPC_CRC->WR_DATA_WORD.DATA = (uint16_t)(__val)
00039 #define CRC32_WRITE32(__val)  LPC_CRC->WR_DATA_DWORD.DATA = (__val)
00040 
00041 #define CRC32_SUM()           LPC_CRC->SUM
00042 
00043 /******************************************************************************
00044  * External global variables
00045  *****************************************************************************/
00046 
00047 /******************************************************************************
00048  * Local variables
00049  *****************************************************************************/
00050 
00051 static uint32_t crcbuff[NUM_CRC_BUFF_ENTRIES];
00052 
00053 /******************************************************************************
00054  * Local Functions
00055  *****************************************************************************/
00056 
00057 
00058 /******************************************************************************
00059  * Public Functions
00060  *****************************************************************************/
00061 
00062 uint32_t crc_Read(FILE* f)
00063 {  
00064   CRC32_INIT();
00065   fseek(f, 0, SEEK_SET);
00066   memset(crcbuff, 0, sizeof(uint32_t)*NUM_CRC_BUFF_ENTRIES);
00067   int numRead = fread(crcbuff, sizeof(uint32_t), 100, f);
00068   while (numRead > 0) {
00069     for (int i = 0; i < numRead; i++) {
00070       CRC32_WRITE32(crcbuff[i]);
00071     }
00072     numRead = fread(crcbuff, sizeof(uint32_t), 100, f);
00073   }
00074   return CRC32_SUM();
00075 }
00076