Re: ANSI C: accesso ai dati di una union

>>
>>
>> struttura:
>>
>> union mnglng {
>>   /* bit access */
>>   struct Bits {
>>     unsigned char bit0:1;
>>     unsigned char bit1:1;
>>     unsigned char bit2:1;
>>     unsigned char bit3:1;
>>     unsigned char bit4:1;
>>     unsigned char bit5:1;
>>     unsigned char bit6:1;
>>     unsigned char bit7:1;
>>   } byte1, byte2, byte3, byte4;
>>   /* byte access */
>>   unsigned char B1;
>>   unsigned char B2;
>>   unsigned char B3;
>>   unsigned char B4;
>>   /* long access */
>>   unsigned long long1;
>>   } uAddr,
la struttura è concettualmente errata in quanto i campi B1 e B4 sono
esattamente gli
stessi, cosi' come la struttua a bit, viso che e' definita nella union.

struct bit8{
       unsigned char bit0:1
       ........
       unsigned char bit7:1
}BIT8_T;

struct bit32{
       unsigned long bit0:1
       ........
       unsigned long bit31:1
}BIT32_T;

union p{
    BIT8_T     bits[4];
    BIT32_T   bitl;
    unsigned char b8[4];
    unsigned long b32;
}x;

// accesso  a bit:
x.bits[0].bit1=........;
x.bits[1].bit1=........;
x.bits[2].bit1=........;
x.bits[3].bit1=........;

// Accesso abit (32)
x.bitl.bit0=....;
............
x.bitl.bit31=....;


// accesso a byte:
x.b8[0]= ........;
x.b8[1]= ........;


bye