вот на 3 и на 5. для 10 нужно поделить на 5 и сдв. вправо на 1 разряд :
u8 div_by3_u8_soft(u8 data_in)
{u16 u16_01, result;
result = u16_01 = data_in;
u16_01 <<= 2; result += u16_01;
u16_01 <<= 2; result += u16_01;
u16_01 <<= 2; result += u16_01;
result += 0x55; //correction
return(result >> 8);
}
u8 div_by3_u8_hmul(u8 data_in)
{return((((u16)data_in * 0x55) + 0x55) >> 8);
}
u16 div_by3_u16_soft(u16 data_in)
{u32 u32_01, result;
result = u32_01 = data_in;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
u32_01 <<= 2; result += u32_01;
result += 0x5555; //correction
return(result >> 16);
}
u16 div_by3_u16_hmul(u16 data_in)
{return((((u32)data_in * 0x5555) + 0x5555) >> 16);
}
u8 div_by5_u8_soft(u8 data_in)
{u16 u16_01, result;
result = u16_01 = data_in;
u16_01 <<= 1; result += u16_01;
u16_01 <<= 3; result += u16_01;
u16_01 <<= 1; result += u16_01;
result += 0x33; //correction
return(result >> 8);
}
u8 div_by5_u8_hmul(u8 data_in)
{return((((u16)data_in * 0x33) + 0x33) >> 8);
}
u16 div_by5_u16_soft(u16 data_in)
{u32 u32_01, result;
result = u32_01 = data_in;
u32_01 <<= 1; result += u32_01;
u32_01 <<= 3; result += u32_01;
u32_01 <<= 1; result += u32_01;
u32_01 <<= 3; result += u32_01;
u32_01 <<= 1; result += u32_01;
u32_01 <<= 3; result += u32_01;
u32_01 <<= 1; result += u32_01;
result += 0x3333; //correction
return(result >> 16);
}
u16 div_by5_u16_hmul(u16 data_in)
{return((((u32)data_in * 0x3333) + 0x3333) >> 16);
}