graphic library and lcd dma.

Hello Ivan,

The LCD's DMA engine does a linear fetch and it would be very cumbersome to use the Graphics library to do so. Alternatively, you can have an external memory where you can do the Graphics library via CPU, and then use the LCD's DMA to copy over the entire frame to the LCD Panel.

I can help with building the DMA routine using the LCD's internal DMA engine, but doing the graphics on an external memory will be very dependent on the kind of application you plan to do. Also note that there is a errata already in place for the LCD-DMA and restarting of the DMA.

Regards
Amit

Hello Amit,

Thank you for your reply. It would be great if you help me to develop my application. How could I connect you?

Regards
Ivan

Hello Ivan

We can discuss this on the forum. That ways we have more users sending their inputs and develop a collateral on the web.,

Regards
Amit

Hi Amit,

At first I want to play the animation.
Now I use GrImaeDraw() and 10 "pnmtoc" images 320x240x8. I see 8-9 fps. It is very slow.
We can use the SD-Card as external memory and use LCD's internal DMA engine to provide image data to LCD.

Regards
Ivan

Hello Ivan,

Since you have a SD-Card, it would be better to have the images in raw bitmap format. The data is then fetched into internal SRAM (or external SDRAM) one image at a time and then using a combination of SysTick Timer and LCD done interrupt they can be put on the panel.

I prefer to use the external SDRAM as I can copy the images quickly using the DMA.

Regards
Amit

Amit,

I don't have an externad SDRAM. May be in the future. Now I have Tiva C Development kit and I can use internal SRAM only.
Can you give me code exaple?

Regards
Ivan

Hello Ivan,

I don't have a code explicitly to do that. But as I suggested, if you can get the raw image from SD card to the SRAM and then use the CPU to write to the LCD directly, then I can help build the LCD DMA part.

Regards
Amit

Hello Amit,

I can do it in a few days and publish code here or send to you by e-mail.

Regards
Ivan

Hello Ivan,

Please attach the code to the post.

Regards
Amit

Hello Amit!

Graph Library don't use the DMA. At last week I made my functions.
Now I want to use LCD DMA in LIDD mode. I try to use LCDIDDDMAWrite(), but it didn't work.
Can you help me or explain how this function works?

Regards
Ivan

Hello Ivan,

How have you set the LCD DMA? Any code post would be useful

Regards
Amit