readdataxlcd.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 91 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   :  ReadDataXLCD
Description     :  This function read the data byte from the 
                   LCD controller. The user must first check 
                   the busy status of the LCD controller by 
                   calling the BusyXLCD() function.The data 
                   read can be from DDRam or CGRam  depending 
                   on the previous SetXXRamAddr( char) that was
                   called.
Input parameters:  none
Return value    :  char data
********************************************************************/

char ReadDataXLCD(void)
{
    char data;
    char temp[8],i;

    /* 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 = 1;                 /* for selecting Data Reg for read */
    Delay18Tcy();
    E_PIN = 1;                  /* for enabling read/write */
    Delay18Tcy();
    temp[7] = (char) DATA_PIN_7;
    temp[7] = temp[7] << 7;
    temp[6] = (char) DATA_PIN_6;
    temp[6] = temp[6] << 6;
    temp[5] = (char) DATA_PIN_5;
    temp[5] = temp[5] << 5;
    temp[4] = (char) DATA_PIN_4;
    temp[4] = temp[4] << 4;

#ifdef EIGHT_BIT_INTERFACE
    temp[3]  = (char) DATA_PIN_3;
    temp[3] = temp[3] << 3;
    temp[2]  = (char) DATA_PIN_2;
    temp[2] = temp[2] << 2;
    temp[1]  = (char) DATA_PIN_1;
    temp[1] = temp[1] << 1;
    temp[0]  = (char) DATA_PIN_0;
    E_PIN =0;                   /* disable read/write */

#else
    E_PIN = 0;                  /* disable read/write */
    RW_PIN = 1;                 /* for read operation */
    RS_PIN = 1;                 /* for selecting DR for read */
    E_PIN = 1;                  /* for enabling read/write */
    Delay18Tcy();

    temp[3] = (char) DATA_PIN_7;
    temp[3] = temp[3] << 3;
    temp[2] = (char) DATA_PIN_6;
    temp[2] = temp[2] << 2;
    temp[1] = (char) DATA_PIN_5;
    temp[1] = temp[1] << 1;
    temp[0] = (char) DATA_PIN_4;

    E_PIN = 0;                  /* disable read/write */
#endif
    for (i=0;i<8;i++)
    {
        data |= temp[i];
    }

    return data;
} /* end of function */

#endif
/* end of file */