HLS Lesson20-实例分析

#include"cordic.h"
void pre_cir_cordic(di_t full_alpha,di_t &alpha,flag_t &flag)
{
if(full_alpha>PI/2)
{
alpha=PI-full_alpha;
flag=2;
}
else if(full_alpha<-PI/2)
{
alpha=-PI-full_alpha;
flag=3;
}
else
{
alpha=full_alpha;
flag=0;
}
}
void cir_cordic_calc(di_t alpha,flag_t flag,do_t &mysin,do_t &mycos,flag_t &flag_delay)
{
const int N = 16;
do_t xi[N];
do_t yi[N];
di_t zi[N];
flag_t flag_delay_a[N];
xi[0]=Kn;
yi[0]=0;
zi[0]=alpha;
flag_delay_a[0]=flag;
const di_t myarctan[16] ={
#include"myarctan.h";
};
int m=0;
loop:
for(m=0;m<N;m++)
{
if(zi[m]>=0)
{
xi[m+1]=xi[m]-(yi[m]>>m);
yi[m+1]=yi[m]+(xi[m]>>m);
zi[m+1]=zi[m]-myarctan[m];
}
else
{
xi[m+1]=xi[m]+(yi[m]>>m);
yi[m+1]=yi[m]-(xi[m]>>m);
zi[m+1]=zi[m]+myarctan[m];
}
flag_delay_a[m+1]=flag_delay_a[m];
}
mysin=yi[N-1];
mycos=xi[N-1];
flag_delay=flag_delay_a[N-1];
}
void post_cir_cordic(do_t mysin,do_t mycos,flag_t flag_delay,do_t &sin_out,do_t &cos_out)
{
switch(int(flag_delay))
{
case 2:sin_out=mysin;cos_out=-mycos;break;
case 3:sin_out=mysin;cos_out=-mycos;break;
default:sin_out=mysin;cos_out=mycos;break;
}
}
void cir_cordic(di_t full_alpha,do_t &sin_out,do_t &cos_out)
{
di_t alpha;
flag_t flag;
do_t mysin;
do_t mycos;
flag_t flag_delay;
pre_cir_cordic(full_alpha,alpha,flag);
cir_cordic_calc(alpha,flag,mysin,mycos,flag_delay);
post_cir_cordic(mysin,mycos,flag_delay,sin_out,cos_out);
}