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Altera_Forum's avatar
Altera_Forum
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20 years ago

i have a problem about pio

i have a problem with pio.

void main

{

unsigned long M=0;

unsigned long N=0;

unsigned long fenzi=0;

unsigned long fenmu=0;

unsigned long em;

M=6997*4*188;

N=7314*204*8*10;

fenzi=M;

fenmu=N;

while(N > 0)

{

em = M % N;

M = N;

N = em;

}

fenzi=fenzi/M;

fenmu=fenmu/M;

}

after i have computer out fenzi and fenmu,i want to trans them to a FPGA module.

the module have three input port (clk,[31:0] fenzi,[31:0] femu).

what should i do ?

may i use 2 pio port?

if so,what is the code?

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    HI, snow

    are u from P.R.C? http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/biggrin.gif

    fenzi? fenmu? http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/biggrin.gif

    they are called "arenumerator" and "denominator" in English http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/tongue.gif

    i know what u mean. and i suggest u can read "Altera Embedded Peripherals Handbook" section 11 "PIO Core with Avalon Interface" and "Nios II Software Developer’s Handbook" section 4 "Developing Programs using the HAL"

    good luck

    http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/cool.gif
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    hi oceanx

    thank you for your help.

    yes, you are right,i am from P.R.C. http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/biggrin.gif

    i have read the releated parts of the handbook,and i have try to use it as follows,

    # include "excalibur.h"

    # include "stdio.h"

    # define clk 57600 //73140# define v 7# define outrate 6840

    unsigned int Gcd(unsigned int M,unsigned int N)

    {

    unsigned int Rem;

    while(N > 0)

    {

    Rem = M % N;

    M = N;

    N = Rem;

    }

    return M;

    }

    void main(void)

    {

    unsigned int wnfenzi,wnfenmu,gcd;

    unsigned int rnfenzi,rnfenmu,rnzheng;

    unsigned int fenzi,fenmu,faqam,qamfenzi,qamfenmu;

    unsigned int inqam;

    unsigned int bo,co;

    //&#35745;&#31639;&#20889;&#26102;&#38047;&#21442;&#25968;

    wnfenzi=outrate*v*188;

    wnfenmu=clk*204*8;

    gcd=Gcd(wnfenzi,wnfenmu);

    wnfenzi=wnfenzi/gcd;

    wnfenmu=wnfenmu/gcd;

    printf("wnfenzi=%d,wnfenmu=%d\n",wnfenzi,wnfenmu);

    na_wnfenzi_pio->np_piodirection=0xffffffff;

    na_wnfenmu_pio->np_piodirection=0xffffffff;

    na_wnfenzi_pio->np_piodata=wnfenzi;

    na_wnfenmu_pio->np_piodata=wnfenmu;

    //&#35745;&#31639;&#35835;&#20351;&#33021;&#21442;&#25968;

    rnfenzi=wnfenmu*47;

    rnfenmu=wnfenzi*2;

    if(rnfenzi>rnfenmu)

    {

    rnzheng=rnfenzi/rnfenmu;

    rnfenzi=rnfenzi-rnfenmu*rnzheng;

    if(rnfenzi==0)

    {

    rnfenmu=2;

    }

    rnfenmu=rnfenmu-1;

    rnfenzi=rnzheng+rnfenzi;

    }

    //&#36755;&#20986;&#20026;rnfenmu(factor),rnzheng(conl_1),rnfenzi(conl_2)

    printf("rnfenzi=%d,rnzheng=%d,rnfenmu=%d\n",rnfenzi,rnzheng,rnfenmu);

    na_rnfenmu_pio->np_piodirection=0xffffffff;

    na_rnzheng_pio->np_piodirection=0xffffffff;

    na_rnfenzi_pio->np_piodirection=0xffffffff;

    na_rnfenmu_pio->np_piodata=rnfenmu;

    na_rnzheng_pio->np_piodata=rnzheng;

    na_rnfenzi_pio->np_piodata=rnfenzi;

    //&#35745;&#31639;&#36870;&#36895;&#29575;&#21305;&#37197;

    faqam=outrate%1000;

    inqam=outrate/1000;

    if(faqam==0)

    {

    fenzi=outrate;

    fenmu=clk;

    }

    gcd=Gcd(faqam,1000);

    qamfenzi=faqam/gcd;

    qamfenmu=1000/gcd;

    fenzi=inqam*qamfenmu+qamfenzi;

    fenmu=clk*qamfenmu;

    printf("fenzi=%d,fenmu=%d\n",fenzi,fenmu);

    na_fenzi_pio->np_piodirection=0xffffffff;

    na_fenmu_pio->np_piodirection=0xffffffff;

    na_fenzi_pio->np_piodata=10;

    co=na_fenzi_pio->np_piodata;

    na_fenmu_pio->np_piodata=fenmu;

    bo=na_fenmu_pio->np_piodata;

    }

    but when i use modelsim to check the result ,i do not understand the waves.

    i mean when the data are written to the pio&#39;s data register,will the pio&#39;s output be always the data? what should i do if i want to output them at a time ,after all the numbers be computed out?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    HI snow

    I suggest u can open the "altera_avalon_pio_regs.h" and "system.h" of NIOS2 project in the IDE and read it carefully.

    use these followed macro:

    IORD_ALTERA_AVALON_PIO_DATA(base)

    IOWR_ALTERA_AVALON_PIO_DATA(base, data)

    Reading the English Datasheet carefully before u program http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif