Page 459 - Programming Microcontrollers in C

444 Chapter 8 MCORE, A RISC Machine

{
LCDDRV.COMMAND=command;
delay(25);
}
/* send data to the LCD */
void LCDData(BYTE data)
{
if (data==’\r’)
LCDDRV.DATA=0X01;
else
LCDDRV.DATA=data;
delay(25);
}
These functions do essentially the same thing. The main difference
is that the Command function writes to the upper byte of the specified
address and the Data function writes to the lower byte of this address.
One other special operation has been put into the Data function. If
the data string contains a ‘\r’ character, it is intended that the cursor
should be returned to the beginning of the line. The 0x01 command
does just that. Otherwise, the data received is sent to the screen for
display. It is recommended that a 25-ms delay be executed after each
write to the LCD system. This delay is included in both of the above
functions.
A sequence of events is needed to bring the LCD display into
operation. The code below first executes the initialization routine
above so that the LCD display is connected to the computer. There
immediately follows a repeated execution of the LCD command 0x03
three times. These instructions prepare the LCD display for operation.
There follows a series of commands: set the display for 2 by 40
character display, turn the display off, clear the display and move the
cursor to the home position, automatically increment cursor position
after each write, turn the display and cursor on, and finally shift the
cursor right after each input. These commands are all executed by
the following code.

/* initialize the LCD */
InitLCD()
{
int i;
initperip(); /* initialize memory block */
for(i=0;i<3;i++)