typedef struct
{
    unsigned char PIN0:                         1;
    unsigned char PIN1:                         1;  
    unsigned char PIN2:                         1;
    unsigned char PIN3:                         1;
    unsigned char PIN4:                         1;
    unsigned char PIN5:                         1;  
    unsigned char PIN6:                         1;
    unsigned char PIN7:                         1;
} F320_Port0_type;

volatile F320_Port0_type *F320_Port0 = 0x80;        // 单片机的P0口的地位为0x80

void main()
{
    P0MDOUT = 0x01;                             // 把P0.0口设置成输出
    F320_Port0->PIN0 = 0;                       // 我想让P0.0口输出低电平，但实际测试下来还是高电平
    while(1);
}

实际上，我就是想用结构体定义的方法来定义寄存器。各位大神帮我看看哪里出了问题，非常感谢。

Thank you in advance!