韌體開發筆記

// apply union to  read and arrange some useful register value 

//============================ contains in *.h

typedef struct {

//register 0

union {
    uint32 interrupt_register_0;
    struct InterruptRegister0{  
        uint8 command;
        uint8 control;
        uint8 feature;
        uint8 feature_ext;
    }isr;

    .....  omit more other register ....

};

}TaskFile;

//------------------------------------------------- defined in IC spec, each 32 bit register has divided into several part

// for example,   InterruptSatausRegister0[31...24] = command

//                        InterruptSatausRegister0[23...16] = control

//                  

typedef struct {                                                          /* DWORD Offset */ /* BYTE Offset */
       volatile uint32 InterruptSatausRegister0;           /* 0x00 */                 /* 0x00 */           

       volatile uint32 InterruptSatausRegister1;           /* 0x01 */                 /* 0x04 */

      ............. omit more other register ....................

}IcRegister;

#define READ_REGISTER(regname, data32)   { (data32) = g_register->regname; }   

#define REGES_BASE              0xC0000000                                       //physicall register address

IcRegister (* const g_register) = (IcRegister *)REGS_BASE;

//============================ contains in *.c

void main()

{

    TaskFile task_file;

    READ_REGISTER(InterruptSatausRegister0, task_file.interrupt_register_0);

    //finally we can get data in task_file easily

    //e.g. task_file.isr.command , task_file.isr.control .... etc. 

}