C error: expression must have a constant value

Question

I am writing some embedded code to interface with an external device over SPI. The device has several registers of varying length and to help keep things straight I have def

Answer 1

I think this may be a compiler issue, and it would be helpful to know your platform and how you are building this code. I just took most of your code, doctored it up to compile it, and compiled on Linux using gcc. There were no warnings.

#include
#include
#include

typedef struct
{
    uint16_t    Signed          :1;  // Register is signed or unsigned
    uint16_t    CommLengthBytes :3;  // The width of the register in bytes 
    uint16_t    Address         :12; // Register address
}ts_register;

int main(int argc, char **argv) {

    static const ts_register    SAGCYC      = {0, 1, 0x000};
    static const ts_register    DISNOLOAD   = {0, 1, 0x001};
    static const ts_register    LCYCMODE    = {0, 1, 0x004};
    static const ts_register    IRMSA       = {0, 4, 0x31A};
    static const ts_register    IRMSB       = {0, 4, 0x31B};
    static const ts_register    VRMS        = {0, 4, 0x31C};

    ts_register regs_to_read[3] = {VRMS, IRMSA, IRMSB};

    return(0);
}

Have you tried casting the values? It's not always the best thing to do, but will get you around the error.

Have you considered creating #define entries?

Also, please be aware consts take a bit of getting used to in C. They do not always behave the way you might expect.