busyxlcd.c

来自「Microchip的官方PIC24H系列16位单片机的外设源程序库。」· C语言 代码 · 共 73 行

#include <p30fxxxx.h>
#include <xlcd.h>

/*External LCD functions are only defined for the following devices */
#if defined(__dsPIC30F5011__) || defined(__dsPIC30F5013__) || defined(__dsPIC30F6010__) || \
    defined(__dsPIC30F6011__) || defined(__dsPIC30F6012__) || defined(__dsPIC30F6013__) || \
    defined(__dsPIC30F6014__)

/*********************************************************************
Function Name:             BusyXLCD
Description:               This function returns the busy status
                           of the LCD Controller.The Busy flag is
                           is MS bit when the Instruction Reg is read
Input parameters:          none
Return value:              char- returns 1 if Busy flag is set, else 0
*********************************************************************/

char BusyXLCD(void)
{
     /* Configure all pins as input */
     TRIS_DATA_PIN_7 = 1;
     TRIS_DATA_PIN_6 = 1;
     TRIS_DATA_PIN_5 = 1;
     TRIS_DATA_PIN_4 = 1;

# ifdef EIGHT_BIT_INTERFACE
     TRIS_DATA_PIN_3 = 1;
     TRIS_DATA_PIN_2 = 1;
     TRIS_DATA_PIN_1 = 1;
     TRIS_DATA_PIN_0 = 1;
#endif

     RW_PIN = 1;           /* for read operation */
     RS_PIN = 0;           /* for selecting AC for read */
     Delay18Tcy();

# ifdef EIGHT_BIT_INTERFACE
     E_PIN = 1;            /* for enabling read/write */
     Delay18Tcy();

     if(DATA_PIN_7)        /* busy flag */
     {
          E_PIN = 0;       /* disable read/write */
          return 1;
     }
     else
     {
          E_PIN = 0;       /* disable read/write */
          return 0;
     }
#endif

 /* FOUR_BIT_INTERFACE   */ 

     E_PIN = 1;            /* for enabling read/write */
     Delay18Tcy();

     if(DATA_PIN_7)        /* busy flag */
     {
          E_PIN = 0;       /* disable read/write */
          return 1;
     }
     else
     {
          E_PIN = 0;       /* disable read/write */
          return 0;
     }

} /* end of function */

#endif
/* end of file */