一個算法
unsigned short SwapBit16(unsigned short Data)
{
int i;
unsigned short Dest;
Dest = 0;
for(i=0;i<8;i++)
Dest |= ((((Data&(1<<i))?1:0)<<(15-i)) + (((Data&(1<<(15-i)))?1:0)<<i));
return Dest;
}
上面這個函數實現對16位數的反轉（倒序變換）。
實現的思路，可以使用如下方法來測試一下。
這個是一個測試函數
#include <stdio.h>
int main(void )
{
int i;
unsigned short Data=45918;
int Dest = 0;
for(i=0;i<8;i++){
printf("Date1 is 0x%x \n",(((Data&(1<<i))?1:0)<<(15-i)));
printf("Date2 is 0x%x \n",(((Data&(1<<(15-i)))?1:0)<<i));
printf("Date2 and Date1 is 0x%x \n",((((Data&(1<<i))?1:0)<<(15-i)))+(((Data&(1<<(15-i)))?1:0)<<i));
Dest |= ((((Data&(1<<i))?1:0)<<(15-i)) + (((Data&(1<<(15-i)))?1:0)<<i));
}
printf("the 0b1011001101011110 end the Date is 0x%x\n",Dest);
return Dest;
}
下面是測試信息結果：
Date1 is 0x0
Date2 is 0x1
Date2 and Date1 is 0x1
Date1 is 0x4000
Date2 is 0x0
Date2 and Date1 is 0x4000
Date1 is 0x2000
Date2 is 0x4
Date2 and Date1 is 0x2004
Date1 is 0x1000
Date2 is 0x8
Date2 and Date1 is 0x1008
Date1 is 0x800
Date2 is 0x0
Date2 and Date1 is 0x800
Date1 is 0x0
Date2 is 0x0
Date2 and Date1 is 0x0
Date1 is 0x200
Date2 is 0x40
Date2 and Date1 is 0x240
Date1 is 0x0
Date2 is 0x80
Date2 and Date1 is 0x80
the 0b1011001101011110 end the Date is 0x7acd
從結果可看出，實現思想是15<-->0,14<-->1,13<-->2,......8<-->7相交換，具體怎麼實現的，你自己可以深入分析一下。。
摘自：gududesiling的專欄
