Pointer made from an integer in C on an embedded platform

问题

I came across the follow line of code:

    #define ADCA (*(volatile ADC_t*)0x200)

It is for embedded C code for an AVR microcontroller. ADC_t is a union.

I know that (volatile ADC_t*)0x200 its a pointer to an absolute memory address but I am still not quite sure what the first * means.

回答1:

That first * dereferences the pointer. In other words ADCA is the contents of the memory at 0x200.

来源：https://stackoverflow.com/questions/7522351/pointer-made-from-an-integer-in-c-on-an-embedded-platform