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[/] [mips789/] [branches/] [avendor/] [bench/] [calc_PI_2/] [cal_pi.c] - Blame information for rev 53

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1 35 mcupro 
/******************************************************************
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 *                                                                *
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 *    Author: Liwei                                               *
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 *                                                                *
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 *    This file is part of the "mips789" project.                 *
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 *    Downloaded from:                                            *
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 *    http://www.opencores.org/pdownloads.cgi/list/mips789        *
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 *                                                                *
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 *    If you encountered any problem, please contact me via       *
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 *    Email:mcupro@opencores.org  or mcupro@163.com               *
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 *                                                                *
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 ******************************************************************/
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14 15 mcupro 
/* This source code is baseed on a 16bit CPU Aquarius in opencores.org */
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/* Thanks the author. */
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/* modified by Liwei 2007-10-13 */
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18 
 
19 
//#define DOS
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#define MIPS
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22 
#ifdef MIPS
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#include "..\..\clib\dvc_lib.h"
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#endif
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26 
#ifdef DOS
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#include "stdio.h"
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#define uart0_putc putchar
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#define uart0_putstr puts
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#endif
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32 
void          longadd(unsigned short *a, unsigned short *b, unsigned short *c);
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void          longsub(unsigned short *a, unsigned short *b, unsigned short *c);
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int           longdiv(unsigned short *a, unsigned short b, unsigned short *c);
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void          calc_pi(void);
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void          disp_oct4(unsigned short x);
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void          disp_pi(void);
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39 35 mcupro 
#define  MAXFIGURE ((1100*2/4)+2) /* should be (N*8)+2 to display correctly */
40 15 mcupro 
 
41 
unsigned short PI[MAXFIGURE];
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unsigned short T1[MAXFIGURE];
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unsigned short T2[MAXFIGURE];
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unsigned short T3[MAXFIGURE];
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46 
/* ============= */
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/*  Main Routine */
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/* ============= */
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void main_sh(void)
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{
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52 35 mcupro 
    uart0_putstr("Calculating.....   ");
53 15 mcupro 
    calc_pi();
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    disp_pi();
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}
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57 
/* ------------------------------------------------- */
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/*  Calculate the Circular Constant Pi */
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/* ------------------------------------------------- */
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/*  (1) Matin's formula */
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/*  PI/4 =  4*arctan(1/5) -   arctan(1/239) */
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/*  PI   = 16*arctan(1/5) - 4*arctan(1/239) */
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/*  Here, arctan(1/p) = 1/p - 1/(3*p^3) + 1/(5*p^5) - 1/(7*p^7) + ... */
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/*  Then,  */
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/*  PI =  (16*1/5     - 4*1/239) */
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/*      - (16*1/3*5^3 - 4*1/3*239^3) */
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/*      + (16*1/5*5^5 - 4*1/5*239^5) */
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/*      - (16*1/7*5^7 - 4*1/7*239^7) */
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/*      +... */
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/*     =  (1/1)*(16*5/(5*5)^1 - 4*239/(239*239)^1) */
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/*      - (1/3)*(16*5/(5*5)^2 - 4*239/(239*239)^2) */
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/*      + (1/5)*(16*5/(5*5)^3 - 4*239/(239*239)^3) */
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/*      - (1/7)*(16*5/(5*5)^4 - 4*239/(239*239)^4) */
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/*      +... */
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/* ------------------------------------------------- */
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/*  (2) Define Arrays for Long Figure Number */
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/*  Each element has Octal 4 figures.  */
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/*      PI[] : Value to be converged to Pi */
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/*      T1[] : (16*  5)/(  5*  5)^n (n=1...) */
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/*      T2[] : ( 4*239)/(239*239)^n (n=1...) */
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/*      T3[] : (-1)*(n+1)*(1/(2n-1))*(T1[]-T2[]) */
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/* ------------------------------------------------- */
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/*  (3) Example */
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/*  n TI[0] TI[1] T2[0] T2[1] T3[0] T3[1] PI[0] PI[1]  */
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/*  0 0080  0000  0956  0000  0000  0000  0000  0000 */
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/*  1 0003  2000  0000  0167  0003  1833  0003  1833 (+) */
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/*  2 0000  1280  0000  0000  0000  0426  0003  1407 (-) */
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/*  3 0000  0051  0000  0000  0000  0010  0003  1417 (+) */
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/*  4 0000  0002  0000  0000  0000  0000  0003  1417 (-) */
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/* ------------------------------------------------- */
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void calc_pi(void)
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{
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    int i;
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    int converged;
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    /* ----------- */
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    /*  Initialize */
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    /* ----------- */
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    converged = 0;
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    for (i=0; i<=MAXFIGURE-1; i++)
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    {
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        PI[i] = 0;
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        T1[i] = 0;
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        T2[i] = 0;
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        T3[i] = 0;
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    }
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    T1[0] = 16*5;
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    T2[0] = 4*239;
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    /* ----------------------------- */
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    /*  repeat until being converged */
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    /* ----------------------------- */
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    i = 1;
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    while (converged == 0)
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    {
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        /* ------------- */
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        /*  Make T1 & T2 */
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        /* ------------- */
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        longdiv(T1,  25, T1);
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        longdiv(T2, 239, T2);
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        longdiv(T2, 239, T2);
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        /* -------- */
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        /*  Make T3 */
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        /* -------- */
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        longsub(T1, T2, T3);
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        converged = longdiv(T3, (unsigned short)(2*i-1), T3);
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        /* if (converged) break; */
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        /* ----------------- */
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        /*  Accumulate to PI */
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        /* ----------------- */
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        if (i%2 != 0)
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            longadd(PI, T3, PI);
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        else
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            longsub(PI, T3, PI);
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        /* ------------ */
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        /*  Increment i */
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        /* ------------ */
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        i++;
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    }
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}
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/* --------- */
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/*  Long Add */
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/* --------- */
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void longadd(unsigned short *a, unsigned short *b, unsigned short *c)
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{
146 
    int i;
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    unsigned short carry;
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    carry = 0;
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    for (i = MAXFIGURE-1; i >= 0; i--)
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    {
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        *(c+i) = *(a+i) + *(b+i) + carry;
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        if (*(c+i) < 10000)
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            carry = 0;
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        else
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        {
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            carry = 1;
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            *(c+i) = *(c+i) - 10000;
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        }
160 
    }
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}
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/* --------- */
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/*  Long Sub */
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/* --------- */
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void longsub(unsigned short *a, unsigned short *b, unsigned short *c)
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{
168 
    int i;
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    unsigned short borrow;
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    unsigned short temp;
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172 
    borrow = 0;
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    for (i = MAXFIGURE-1; i >= 0; i--)
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    {
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        temp = *(b+i) + borrow;
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        if (*(a+i) >= temp)
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        {
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            *(c+i) = *(a+i) - temp;
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            borrow = 0;
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        }
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        else
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        {
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            *(c+i) = 10000 + *(a+i) - temp;
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            borrow = 1;
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        }
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    }
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}
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/* --------- */
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/*  Long Div */
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/* --------- */
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int longdiv(unsigned short *a, unsigned short b, unsigned short *c)
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{
194 
    int i;
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    int conv;
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    unsigned long al, bl, cl, dvd, rem;
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198 
    conv = 1;
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    rem = 0;
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    for (i = 0; i <= MAXFIGURE-1; i++)
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    {
202 
        al = (unsigned long) *(a+i);
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        bl = (unsigned long) b;
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        cl = (unsigned long) *(c+i);
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206 
        dvd = al + rem;
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        cl = dvd / b;
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        rem    = (dvd - cl * bl) * 10000;
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        if (cl > 0) conv = 0;
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        *(c+i) = (unsigned short) cl;
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    }
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    return conv;
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}
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/* ----------- */
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/*  Display Pi */
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/* ----------- */
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void disp_pi(void)
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{
220 
    int i, j;
221 35 mcupro 
    uart0_putstr("Calculating DONE  ");
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    uart0_putstr("Pi = 3.");
223 15 mcupro 
  /*  while(1)*/
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    {
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        for (i = 0; i < (MAXFIGURE - 2) / 8; i++)
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        {
227 
             for (j = 0; j < 8; j++)
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            {
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  /*               if (j == 0) lcd_pos(0);  */
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  /*               if (j == 4) lcd_pos(16); */
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                disp_oct4(*(PI + i*8 + j + 1));
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             }
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        }
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    }
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}
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237 
/* ------------------- */
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/*  Display Oct 4 digit */
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/* ------------------- */
240 
 
241 
void disp_oct4(unsigned short x)
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{
243 
 
244 
    unsigned short d;
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    d = x / 1000;
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    x = x - d * 1000;
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    uart0_putc((char)(d+0x30));
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    d = x / 100;
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    x = x - d * 100;
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    uart0_putc((char)(d+0x30));
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    d = x / 10;
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    x = x - d * 10;
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    uart0_putc((char)(d+0x30));
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    uart0_putc((char)(x+0x30));
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}
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257 
#ifdef MIPS
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main2()
259 
#endif
260 
 
261 
#ifdef DOS
262 
main()
263 
#endif
264 
{
265 
 
266 
unsigned char i=0;
267 
 
268 
 
269 
for(;;)
270 35 mcupro 
{
271 
 uart0_putstr("Hello CPU World ,this is  MIPS789...\n");
272 
calc_pi();
273 15 mcupro 
    disp_pi();
274 
#ifdef MIPS
275 
dis_byte(i++);
276 
while(get_key1()==0)      ;
277 
#endif
278 
 
279 
#ifdef DOS
280 
getchar();
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#endif
282 
}
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}

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