C volatile variables and Cache Memory

Question

Cache is controlled by cache hardware transparently to processor, so if we use volatile variables in C program, how is it guaranteed that my program reads data each time fro

Answer 1

using the _Uncached keyword may help in embedded OS , like MQX

#define MEM_READ(addr)       (*((volatile _Uncached unsigned int *)(addr)))
#define MEM_WRITE(addr,data) (*((volatile _Uncached unsigned int *)(addr)) = data)