bit操作函数

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// main.c

// jnjd

// Created by syw on 14-3-14.

#include <stdio.h>

#define TRUE 0

#define FALSE 1

//#define MAX_FRAME_NUM 10000

typedef unsigned int UINT32;

typedef unsigned char UINT8;

typedef unsigned short UINT16;

typedef struct

{

UINT8 * pByte;

UINT8 ucBitPos;

}STRU_POS;

typedef struct

{

UINT16 uhwKey;

UINT8 ucOpCode;

UINT8 ucPara0;

UINT8 ucPara1;

}STRU_FRAME;

typedef struct

{

STRU_FRAME * pstruHostFrame;

STRU_POS struStart;

STRU_POS struEnd;

}STRU_CTRL;

typedef struct

{

UINT32 uwFrameCnt;

STRU_FRAME struFrame[MAX_FRAME_NUM];

}STRU_FRAME_LIST;

STRU_FRAME_LIST gstruFrame;

STRU_CTRL gCtrl;

UINT8 * pgIn;

UINT8 * pgOut;

UINT8 * pgEndBound;

/*************************************************************************

函数功能：从指定位置获取连续bit 字段；

ucBitNum 待获取的bit数，最多32bit；

pstruPos 待获取的起始位置

返回：获取到的字段

**************************************************************************/

UINT32 BitFieldGet(UINT8 ucBitNum,STRU_POS * pstruPos)

{

UINT32 uwVal,uwi,uwTmp;

STRU_POS struPos;

struPos.pByte = pstruPos->pByte;

struPos.ucBitPos = pstruPos->ucBitPos;

uwVal =0;

for(uwi =0;uwi < ucBitNum;uwi++)

{

uwTmp =0x01&((struPos.pByte[0])>>(struPos.ucBitPos));

uwTmp = uwTmp<<uwi;

uwVal = uwVal+uwTmp;

/* Update position; */

if(struPos.ucBitPos <7)

{(struPos.ucBitPos)++;}

else

{

struPos.ucBitPos =0;

(struPos.pByte)++;

}

return uwVal;

}

/*************************************************************************

函数功能：检测当前位置是否为有效pattern

ucTotalBitNum 待检测pattern的bit数，最多32bit；

uwPattern 待检测pattern

pstruPos 待检测的起始位置

返回： 0 ：检测到 pattern

1：未检测到pattern

**************************************************************************/

UINT32 PatternCheck(UINT8 ucTotalBitNum,UINT32 uwPattern,STRU_POS * pstruPos)

{

UINT8 aucBit;

UINT32 uwi;

UINT8 ucByte;

STRU_POS struPos;

struPos.pByte = pstruPos->pByte;

struPos.ucBitPos = pstruPos->ucBitPos;

if (ucTotalBitNum >32)

{

return1;

}

for(uwi =0;uwi < ucTotalBitNum;uwi++)

{

ucByte = struPos.pByte[0];

aucBit =0x01&(ucByte>>(struPos.ucBitPos));

if(aucBit != (0x01&(uwPattern>>uwi)))

{return1;}

if(struPos.ucBitPos <7)

{(struPos.ucBitPos)++;}

else

{

struPos.ucBitPos =0;

(struPos.pByte)++;

}

return0;

}

/*************************************************************************

函数功能：在连续的bit流中检测指定图案并记录patern起始 bit和字节位置；

pstruIn 搜索起始位置；实时修改；

ucTotalBitNum 待搜索pattern的bit数

uwPattern 待搜索pattern

返回： 0：搜索成功；

1：搜索失败；

**************************************************************************/

UINT32 PatternSearch(STRU_POS * pstruIn,UINT8 ucTotalBitNum,UINT32 uwPattern)

{

STRU_POS struPos;

UINT32 uwFlag;

UINT32 uwDiff;

UINT8 ucRemainByteNum;

UINT8 ucRemainBitNum;

uwFlag =1;

ucRemainByteNum = ucTotalBitNum/8;

ucRemainBitNum = ucTotalBitNum%8;

while (1 == uwFlag)

{

uwDiff = (UINT32)pgEndBound - (UINT32)(pstruIn->pByte);

if((uwDiff < ucRemainByteNum)

||((ucRemainByteNum == uwDiff)&&(pstruIn->ucBitPos>(8-ucRemainBitNum)))

)

{

returnFALSE;

}

uwFlag =PatternCheck(ucTotalBitNum, uwPattern, pstruIn);

/* Keep the position; */

struPos.pByte = pstruIn->pByte;

struPos.ucBitPos = pstruIn->ucBitPos;

/* Update the position; */

if(pstruIn->ucBitPos <7)

{

(pstruIn->ucBitPos)++;

}

else

{

pstruIn->ucBitPos =0;

(pstruIn->pByte++);

}

/* Record the pattern position; */

pstruIn->ucBitPos = struPos.ucBitPos;

pstruIn->pByte = struPos.pByte;

return TRUE;

}

/************************************************************************************************************/

int main(int argc,constchar * argv[])

{

UINT8 aIn[3] = {0x12,0x33,0x58};

STRU_POS struPos;

UINT32 uwVal;

struPos.pByte = &aIn[1];

struPos.ucBitPos =6;

00010010

00110011

01011000

uwVal =BitFieldGet(7, &struPos);

printf("%d\n",uwVal);

//TestCase1();

// insert code here...

printf("Hello, World!\n");

return0;

}

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