text: #ifndef _DIGITAL_H_
  #define _DIGITAL_H_
  
  /*
   * digital bits addr(uint8)
   */
  #define DIGITAL_REG_ADDR            ((volatile unsigned char *)0x07FF0000)
  
  #define DIGITAL_DSW1                0x01
  #define DIGITAL_DSW2                0x02
  #define DIGITAL_LED1                0x04
  #define DIGITAL_LED2                0x08
  #define DIGITAL_LED3                0x10
  
  #endif /* _DIGITAL_H_ */