bitband.c

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/****************************************Copyright (c)**************************************************
**                               Guangzhou ZHIYUAN electronics Co.,LTD.
**                                     
**                                 http://www.embedtools.com
**
**--------------File Info-------------------------------------------------------------------------------
** File Name: BitBand.c
** Last modified Date: 2006-11-15 
** Last Version: v1.0
** Description: Stellaris系列单片机BitBand(位操作)
** 
**------------------------------------------------------------------------------------------------------
** Created By: Zhou Lishan
** Created date: 2006-11-15 
** Version: v1.0
** Descriptions:
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Description:
**
********************************************************************************************************/

#define HWREG(x)            (*((volatile unsigned long *)(x)))
#define HWREGBITW(x, b)    HWREG(((unsigned long)(x) & 0xF0000000) | 0x02000000 | \
                           (((unsigned long)(x) & 0x000FFFFF) << 5) | ((b) << 2))
unsigned long g_ulValue;
int main(void)
{
    unsigned long ulErrors, ulIdx;
    g_ulValue = 0;
    ulErrors = 0;
    for(ulIdx = 0; ulIdx < 32; ulIdx++)
    {   HWREGBITW(&g_ulValue, 31 - ulIdx) = (0x12345678 >> (31 - ulIdx)) & 1;		// 位写入
    }
    if(g_ulValue != 0x12345678)							// 变量的值与位写入的值是否相等
    {   ulErrors++;
    }

// 以位方式读出g_ulValue各位，与0xdecafbad比较
    for(ulIdx = 0; ulIdx < 32; ulIdx++)
    {
        if(HWREGBITW(&g_ulValue, ulIdx) != ((0x12345678 >> ulIdx) & 1))
        {
            ulErrors++;
        }
    }

    if(ulErrors)
    {
       while(1);		// 位操作出错
    }

    while(1);			// 实验正常完成
}