S1D1370002A1 single/dual screen trouble?


New member
I have bought a CFAG320240CX-TTI-T with a S1D1370002A1 controller.
I am able to initialize it and to write some letter on the screen. But only in dual screen mode.

If I put WS (bit 3 of the first parameter of System set command) to 0 wich it is suppose to mean that i want to use the LCD in single screen mode, there is only some strange vertical lines...

Also, when I write anything at 0x0000 (in the first block), it is repeated at the start of the third block even if the third block start addresse is 0x4B00

Here is the configuration of some bits who select type of display:
WS = 1 -->Dual screen
OV = 0
DM2 = 0
DM1 = 0

What could be the problem?

Thanks for your help
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

CF Support

You should check out the example code for that display, you can find it here. It is very well documented and might shed some light on the subject.


New member
thanks for your help but I am not using pc parrallel port but a DS89C420 ucontroller.
Also, I tried the example code of the Datasheet S1D13700 without success....Anything that is show on first line of the screen is repeated at the middle line.... I set the "various parameter" to have a 40 caractere per lines and 30 lines by screen....
what else do you think could creat this?


New member

About the dual display,
Is it possible that it is broke? Can it be a material trouble? I know the screen are tested before shipped.
But even when the display is off, everything that is on the upper side of the screen (120 first lines) are also exactly the same on the lower side (120 las lines).

When display is off, some horizontal lines appears. on both side.

When display is on, the cursor is blinking both on the upper side and the lower. Is it possible to have two cursor blinking together on the screen?

Thanks for your answer