As the final version of the display is comming soon,  we start to finalize the display module design of this module.
Based on the actual testing which wastes us quite a lot of time, we found two bugs in software and hardware.
It is found that the 4GDL compiler has its own problem in compiling process. It is found that, if we use more than 4 or 5 "gosub()" function, the compiling will get problem that cause the compiler itself working un-properly and also the compiled program also cannot run properly. In order to avoid it, we need to limit the use of "gosub" functions.
On the other hand, we find that the signal cannot be continously sent to the graphics processor. By make the actual testing on the transmission, we find the best solution is to continously transmit 5 byte and stop for about 1ms under band rate 9600. If the band rate is higer, it needs to insert more delay.