Serial RAM to be used as a buffer for a gLCD module is useless. It is way way too slow.

The fact of the matter is that the T6963C chip is a piece of junk for making a fast graphics application. Good gosh....you even have to poll status on this silly part even when you put it into the fastest possible loading mode known as "AUTO WRITE" where the address pointer auto increments. Toshiba does not even recommend using the chip in a non-polled mode where you would simply use some program step delay in lieu of the status polling...they claim that data corruption could always happen if the proper status is not polled!!

Compare this with other popular gLCD driver chips from Samsung and others that, once a row access is setup in motion, it is possible to hose bytes to the controller display memory at the bus cycle time of the display controller !! I have even used displays of this type where the two wire serial mode to the display was used as a write only interface. I have run the data clocking for such displays at just under 4 MHz bit rate and achieved getting bytes to the display at a rate of about 500K bytes per second. If you consider that the optimal way to run a graphics display of this type is with a RAM image buffer and support for copying whole rows from the buffer memory to the display controller then the average time per byte is very nearly equal to the raw data transfer rate. For your type display of 240 columns a vertical raster controller can write a whole row data in 240 write cycles. The additional setup time at the start of each block row write may take say 16 more write cycles. That is a total of 256 writes per raster row. A 128 pixel/column display such as yours has 16 if these rows to paint the whole display. Thus a rough estimate of achievable full display update time is: (500K bytes/sec) / ((256 * 16) bytes/screen) ~== 122 screens per second update rate.

I say get your self a solution with a fast RAM buffer on board the processor and a vertical byte raster display controleller and you can easily scroll the display so fast that the LCD pixels will smear into un-readability.

Michael Karas