[SOLVED] GLCD 12864 - Busy check - Unrolled code

[atferrari]

glcd12864

I am about to start writing code in Assembler (PIC 18F) to handle the basics of a GLCD (definitely trying to reinvent the wheel, which, by the way, I found nowhere up to now).

Two basic questions:

a) Given the need to check the busy flag, is it better to do it immedately after writing and leave with the "homework done" or leave it unchecked and do it prior writing the next time? (Second option gives the chance to find the BUSY flag already low reducing the waiting time. Am I right?)

b) For the different basic routines is it better to write them totally unrolled or make them compact using as much as possible CALL / BRA instructions?

 

[wp100]

12864 busy

Hi,

We found that it worked best if tested straight after each data or command write.
The delay is minimal, although have not actually timed it.

Some web comment suggests that it only needs checking if the clock speed is over 12 meg, although have not tried that even though we were using 4 meg

For this project you really do need to keep your code in simple subroutines, when you output a screenfull of data it would not be practical 'unroll' the code.
We used 4 macros and 14 subroutines to the main code which outputed 8x16 lines of text and a full screen bitmap image.