• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

CFAG240128L 40 columns and 6x8 font

Hans Chr

New member

The T6963 states that in order to have 40 columns you need to set MD2 low (32 cols if high). But then the font must be 6x8 and that is selected by FS1 set to high (8x8 if low).

In the datasheet for the lcd it says that MD2 and FS (probably meaning FS1, there are two, FS0 as well!) are the same signals!

So how can I manage to have 40 characters on the same line on this LCD?

I guess I am stucked with 40 columns, but with 8x8 font :eek: giving me only 30 chars (see below).

For reference: 240 pixels : 6 pixels/char = 40 chars (MD2=LOW and FS1=HIGH) , not possible with lcd???

240 : 8 = 30 chars (both low) , all 240 pixels used, but only giving 30 chars.

FS1=HIGH, MD2=HIGH : giving 32 columns with 6x8 font. not possible to get access to the whole screen! so the 8 characters on the right is not reachable.

Am I missing something? If the two signals are inverted versions of one another, then it would be ok!
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

CF Support

Unfortunately what I've seen is that using the 6x8 mode generally makes the display behave in a manner that is counter intuitive. I've never been able to make any T6963 display work "correctly" using 6x8, though it is possible that I was missing something undocumented (in the Toshiba datasheet).

Hans Chr

New member

By looking in the datasheet, if you put MD3=LOW, then you will have 64(MD2=HIGH) or 80(MD2=LOW) columns. It does not matter what size the LCD really is. The data will just be written in ram, but will not be shown on LCD if out of pixel range.

The problem is that when you set FS1 for 6x8 mode, and because you have hard-wired this signal to MD2, you will only get 32 columns. By setting MD2 and MD3 (independantly) for 80 columns you will be able to use both 6x8 and 8x8 font for the whole row (line). And you could possible write out of lcd area as well, and then later by setting the start address differently you could scroll to the area already written to in ram to be displayed.

I guess that in my opinion the columns range should be as large as possible. The font selection only specifies at what pixel intervals the next column will be.

So, would it be possible for your LCD to either set the MD3 to LOW (guessing that it already is HIGH), or keeping MD3=HIGH and make a cut on the pcb trace for the MD2 and set this to LOW and FS1 to HIGH=6x8.
If these traces on pcb are easy to see, the hack should be possible.

here is a link to the datasheet:

http://home.comet.bg/datasheets/LCD Grafical/T6963c.pdf

look at page 3 for MD and FS signals and you will see what I mean.

Hans Chr

New member
I was looking in the datasheet a bit more, and there is a command for setting the text area (number of columns). So I was thinking that I could set it to 40 columns, even though it was set to 32 by hardware. The problem is that this does not work. However the command works if I set the number of columns less than 32! So this just justifies that all LCD modules with t6963 should be set to maximum columns. Then the user could issue the software command and set the number of columns that is prefered!

I believe there is no workaround for this problem. I really hope that the hardware could be fixed to work the proper way.

Best Regards


Hans Chr

New member
Dear CrystalFontz,

I am still waiting for your response to this subject.

For future LCD revisions I guess that MD3 should be hardwired differently?


hans chr

CF Support

Thank you for your message.

I can say that the design decisions made by our factory engineers were made for reasons that are not known to me, but also that we're not terribly likely to re-tool the board in order to make this particular part an extremely large character LCD.

That said, I have contacted our factory engineer to see if I can give you an explanation, or at least a definitive answer as to whether or not this can be worked around, or if it will be changed in the future.