What are Dual/Single Panel LCD's?

[Garph]

Hi All,

This is my first time programming a micro-controller and I'm stuck on a hardware definition.

The ARM LCD controller Data Sheet[1] says:

"The LCD controller can operate in single-panel or dual-panel modes when connected to the associated multiplexed LCD."

"In dual panel mode, the DMA FIFOs are filled up in an alternating fashion via a single DMA request. In single panel mode, the DMA FIFOs are filled up in a sequential fashion from a single DMA request."

What are single and dual panel LCDs? How do I know which I am using?

[1] ARM LCD Controller Data Sheet: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0121d/ch01s07s02.html
[2] LCD Datasheet: http://www.nxp.com/assets/documents/data/en/supporting-information/RK043FN02H-CT.pdf

[james_s]

Sounds to me like it's referring to something like the old "dual scan" LCD panels. In those a single display is electrically split up into two smaller displays, reducing the number of elements that have to be scanned and improving the quality of the display.

[amyk]

The first line makes it sound like the controller can drive either 1 or 2 LCDs, but the second line seems more like it's referring to LVDS "interlacing" where even and odd-column pixels are driven from separate lanes.

[Buriedcode]

It is indeed referring to old 'STN' passive LCD's.  Thus the 'monochrome' in the title of that section.

These required 4-bit data, data clock, line clock, frame sync etc..  For displays >320x240, such as the 640x480, they were split into upper and lower sections that were updated at the same time, so the data interface was 8-bit: 4-bit upper panel, 4 bit lower. I have one such display and they are remarkably hard to find controllers for!  But they are old old, slow and depreciated.

As you're using a TFT display then you should be using 'LCD_TFT' bit in the control register.