方法C:

#define bwMCDR2_ADDRESS 4

#define bsMCDR2_ADDRESS 17

int BIT_MASK (int_bf)

{

return ((IU<<(bw##_bf))-1)<<(bs##_bf);

}

void SET_BITS(int_dst,int_bf,int_val)

{

_dst=((_dst) & ~ (BIT_MASK(_bf)))I\ (((_val)<<<(bs##_bf))&(BIT_MASK(_bf)))

}

SET_BITS(MCDR2,MCDR2_ADDRESS,RegisterNumber);
方法D:

#define bwMCDR2_ADDRESS 4

#define bsMCDR2_ADDRESS 17

#define bmMCDR2_ADDRESS BIT_MASK (MCDR2_ADDRESS)

#define BIT_MASK(_bf)(((1U<<(bw##_bf))-1)<< (bs##_bf)

#define SET_BITS(_dst,_bf,_val)\ ((_dst)=((_dst)&~(BIT_MASK(_bf)))I (((_val)<<(bs##_bf))&(BIT_MASK(_bf))))

SET_BITS(MCDR2,MCDR2_ADDRESS,RegisterNumber);

这两个程序不太看懂啊。能解释一下下吗？