Keil + LCD 44780U display

[buffalo101]

Hello,

I am supposed to play a little with a HD44780U (LCD-II) display and this platform:

http://www.cs.ucv.ro/~lemeni/Downloads/Sistem%20de%20dezvoltare.pdf

A template for the C program is included here:

http://www.cs.ucv.ro/~lemeni/labmicro/Lab45.zip

I can't understand certain things about interfacing the LCD display. For instance, the *ports* are defined like this:

#define IR_WR	0x100
#define STAT_RD 0x102
#define DR_WR	0x101
#define DR_RD	0x103

Then, I would address these ports with the XBYTE keyword.

XBYTE[IR_WR]=0x00;

From the LCD documentation:

**broken link removed**

A short example is given:

For the "Clear display command", RS=0, R/W#=0 and DB(7:0)=0000_0001b=01h. To send this instruction, we use:

XBYTE[IR_WR]=1;

My question is this: how do I include the RS, R/W# in a 8bit instruction?! or how precisely do I form the instructions?

And also, how do I read the BusyFlag? I think I should first set RS=0, R/W#=1 and then check for Bit7 on the DR_RD (data_register read?) port.

Thanks in advance!

 

[ckshivaram]

rs r/w and enablepins are bit addressable so you need to declare it as bit addressable....

you need to declare it as
sbit rs=P3^5;
sbit en = P3^4;

if you dont want to use busy pin then permanently ground the r/w pin on the hardware....