How can get the CPU unique ID?

[wangyiming]

Thanks

[moliate]

Assuming the processor supports unique serial number:

#define cpuid __asm __emit 0fh __asm __emit 0a2h
UINT PSN, ID1, ID2, ID3;

__asm
{
mov eax, 01H
cpuid
mov PSN, edx
}

if (PSN&0x20000 0x40000) //Check bit 18 if serial number is available
{
__asm
{
mov eax, 01H
cpuid
mov ID1, eax
mov eax, 03H
cpuid
mov ID2, edx
mov ID3, ecx
}
}
else
{//Processor does not support unique ID
}

If everything works out ID1, ID2, ID3 should contain the unique 96 bit ID. I havn´t tested the code since I don´t have a PIII, but I hope it works... More info on cpuid here (pdf). Hope this helps /moliate

[wangyiming]

Thank you very much

[moliate]

There was a litte bug in the sample program... :-O Bit 18 is 0x40000, not 0x20000. If you havn't discovered it yourself I think I should save you some trouble.... /moliate