Software » Campo » Biwak

constexpr unsigned int lpdiv100( unsigned int x )
{
   // Valid till 102400
   return( ( ( x + 1 ) * 0xA3D7 ) >> 22 );
};

static_assert( lpdiv100(2099) == 20 );
static_assert( lpdiv100(2100) == 21 );

The RTC Alarm has to be checked for the next (!) alarm.

    for(int i1=0; i1<102400-1; i1++)
    {
       if( (i1/100) != lpdiv100(i1) )
       {
          printf( "Error: %d: %d\n", i1, lpdiv100(i1) );
          //return( 1 );
       }
    }

    for(ui i1=0; i1< 32; i1++)
    {
       ui m=(1ull << i1)/100ull;
       ui r = ( 10240 * m ) >> i1;
       ui d=(1ull << i1)-( m * 100ull);
       ui pm=(d*1000000)/m;
       if( r == 102 )
       {
         printf("m=0x%X; s=%d; r=%d; fehler=%dpm\n", m, i1, r, pm);
              // "102400/100=%d\n", r);
       }
    }