Thread: How to get sequence of bits through Functional Call

Originally Posted by SarasMuthu

Please look below code, its displaying only Single bit insted of sequence of bits.

I fixed the typo errors in your code, compiled and ran it, and got:

Code:

110111111010011001101010001100000111010101011111001571555768

The first part looks like a sequence of bits to me. The last part is because you botched the return value of the function: I have no idea what you actually want PRBS to return, but it surely isn't a pointer to unsigned int coerced into an int.

Thanks for your response. Sorry, i have uploaded wrong code, and now i am updating with New source code. Actually what i want means, in my source code, i need not use printf statement function. My result should be sequence of random bits 0`s and 1`s.

Code:

int *Randombits( ) {

   static int  reg;
int bit;
int  load_data =0xACF5;
int i=0;
 reg = load_data;


for (i=0;i<=32;i++)
 {

        bit  = ((reg >> 0) ^ (reg >> 2) ^ (reg >> 3) ^ (reg >> 5) ) & 1;
        reg =  (reg >> 1) | (bit << 15);
      reg [i] = bit;  /// SHOWING ERROR

   }

   return reg;  // SHOWING ERROR
}

/* main function to call above defined function */
int main () {

   /* a pointer to an int */
   int *p;
   int i;

   p = Randombits();

   for ( i = 0; i < 30;i++ )
   {
      printf("*(p + [%d]) : %d\n", i, *(p + i) );
   }

   return 0;

Then you need to figure out what in the world you actually want to return. It looks like you want to return a single random bit, but then of course you cannot print a sequence of random bits with a single call to PRBS. Perhaps:

Code:

#include <stdio.h>

int PRBS(void)
{
    static unsigned int lfsr = 0xCD;

    int bit = ((lfsr >> 0) ^ (lfsr >> 2) ^ (lfsr >> 3) ^ (lfsr >> 4)) & 1;
    lfsr = (lfsr >> 1) | (bit << 7);
    return bit;
}

int main(void)
{
    int i;
    for (i = 0; i < 50; i++)
    {
        putchar('0' + PRBS());
    }
    putchar('\n');
    return 0;
}

Try

Code:

int *Randombits( ) {
  
   static int  result[33];
int bit;
int i=0;
static int reg = 0xACF5;  // starting value, generates different patterns with each call to Randombits
  
  
for (i=0;i<=32;i++)
 {
  
        bit  = ((reg >> 0) ^ (reg >> 2) ^ (reg >> 3) ^ (reg >> 5) ) & 1;
        reg =  (reg >> 1) | (bit << 15);
      result [i] = bit;
  
   }
  
   return result;
}

Originally Posted by SarasMuthu

Sorry, i have uploaded wrong code, and now i am updating with New source code.

Originally Posted by SarasMuthu

Sorry, i have uploaded wrong code, and now i am updating with New source code.

* waits for SarasMuthu to upload the new source code again as responding to yet another wrong code would be pointless *

Also here -> For Pseudo_random Number Generator :why We Using "static" Keyw - C And C++ | Dream.In.Code