Question

Anyone can explain in details what the following macro does?

#define write_XDATA(address,value) (((char *)0x010000) [address]=value)

thx!

Answer 1

You use it:

write_XDATA( Address, Value );

and it is expanded:

((char*)0x010000)[Address]=Value;

which is equivalent to the following:

char* baseAddress = (char*)0x010000;
*(baseAddress + Address) = Value;

so basically it writes a byte stored in Value at the address 0x010000 + Address.