Advanced Parallel I/O - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 337

temp 5 cmd; // save a copy of the command

cmd & 5 0xF0; // clear out the lower 4 bits

LCD_DAT & 5 ( , LCD_RS); // select LCD instruction register

LCD_DAT | 5 LCD_E; // pull E signal to high

cmd ..5 2; // shift to match LCD data pins

LCD_DAT 5 cmd | LCD_E; // output upper 4 bits, E, and RS

asm (“nop”); // dummy statements to lengthen E

asm (“nop”); // “

asm (“nop”);

LCD_DAT & 5 ( , LCD_E); // pull E signal to low

cmd 5 temp & 0x0F; // extract the lower 4 bits

LCD_DAT | 5 LCD_E; // pull E to high

cmd ,,5 2; // shift to match LCD data pins

LCD_DAT 5 cmd | LCD_E; // output upper 4 bits, E, and RS

asm(“nop”); // dummy statements to lengthen E

asm(“nop”); // “

asm(“nop”);

LCD_DAT & 5 ( , LCD_E); // pull E-clock to low

delayby50us(1); // wait until the command is complete

}
void openLCD(void)
{

LCD_DIR 5 0xFF; // configure LCD_DAT port for output

delayby10ms(10);

cmd2LCD(0x28); // set 4-bit data, 2-line display, 5 3 7 font

cmd2LCD(0x0F); // turn on display, cursor, blinking

cmd2LCD(0x06); // move cursor right

cmd2LCD(0x01); // clear screen, move cursor to home

delayby1ms(2); // wait until clear display command is complete

}
void putcLCD(char cx)
{

char temp;

temp 5 cx;

LCD_DAT | 5 LCD_RS; // select LCD data register

LCD_DAT | 5 LCD_E; // pull E signal to high

cx & 5 0xF0; // clear the lower 4 bits

cx ..5 2; // shift to match the LCD data pins

LCD_DAT 5 cx|LCD_E_RS; // output upper 4 bits, E, and RS

asm(“nop”); // dummy statements to lengthen E

asm(“nop”); // “

asm(“nop”);

LCD_DAT & 5 ( , LCD_E); // pull E to low

cx 5 temp & 0x0F; // get the lower 4 bits

LCD_DAT | 5 LCD_E; // pull E to high

cx ,,5 2; // shift to match the LCD data pins

LCD_DAT 5 cx|LCD_E_RS; // output lower 4 bits, E, and RS

asm(“nop”); // dummy statements to lengthen E

asm(“nop”); // “

asm(“nop”);

LCD_DAT & 5 ( , LCD_E); // pull E to low