整数开方运算的DSP实现

开方运算的DSP实现

(2014-04-07 10:59:36)

转载▼

标签： c dsp

分类：DSP

//===============================================

//函数名：VSqrt3

//功能： 实现对32位定点数的开方

//性能： 60M主频28015硬件下运行时间小于10us

//转自：http://read.pudn.com/downloads180/sourcecode/mpi/840129/sqrt.c__.htm

unsigned longVSqrt3(unsigned longx )

{

unsigned longx1;

ints=1;

unsigned longg0,g1;

if(x<=1) returnx;

x1=x-1;

if(x1>65535)

{

s+=8;

x1>>=16;

}

if(x1>255)

{

s+=4;

x1>>=8;

}

if(x1>15)

{

s+=2;

x1>>=4;

}

if(x1>3)

{

s+=1;

}

g0=1;

g0=g0<<s;

g1 =(g0 +(x>>s))>>1;

while(g1

{

g0=g1;

g1=(g0+x/g0)>>1;

}

returng0;

}

//===============================================