比如：
void           _never_executed(void );

unsigned short _bcd_add_short(unsigned short, unsigned short);
unsigned long  _bcd_add_long(unsigned long, unsigned long);

unsigned int   _even_in_range(unsigned int, unsigned int);
void           _op_code(unsigned short);
void           _data20_write_char(unsigned long, unsigned char);
void           _data20_write_short(unsigned long, unsigned short);
void           _data20_write_long(unsigned long, unsigned long);
unsigned char  _data20_read_char(unsigned long);
unsigned short _data20_read_short(unsigned long);
unsigned long  _data20_read_long(unsigned long);
unsigned short _get_interrupt_state(void);
void           _set_interrupt_state(unsigned short);
unsigned short _get_SP_register(void);
void           _set_SP_register(unsigned short);
话说有讲解这些东西的资料没？ 此帖出自小平头技术问答