题目

union的定义
union //程序标志位
{
uint16 Register;
struct
{
uint8 bus_reset :1;
uint8 suspend :1;
uint8 remote_wakeup :1;
uint8 int_isr :1;
uint8 not_end :1;
uint8 usb_idle :1;
uint8 usb_busy :1;
uint8 setup_packet_in :1;
uint8 setup_packet_out :1;
uint8 set_addr :1;
uint8 usb_endp0_in :1;
uint8 usb_endp2_in :1;
uint8 usb_endp2_out :1;
}flags;
}usb_flags;

提问时间：2021-03-19

答案

这里的1意思是定义1个位的大小来存储1或0两中状态