topic Re: 5329 + TFT : flicker problem in ColdFire/68K Microcontrollers and Processors

5329 + TFT : flicker problem

nafiton — Mon, 25 Sep 2006 15:30:03 GMT

Hello

I connected a 640*480 TFT to a Cobra 5329 board. I have no image on screen with the original software, so we try with a test program. After a few tests, I went back to the original freescale driver values and I got the tft to work. But I have some flicker on the screen being the pixel clock frequency 7MHZ and the vertical refresh 14 Hz. I start to change the MCF_LCDC_LPCR_PCD value to get higher frequency but then the screen lose the synchronization and I am not able to adjust it.

I must be losing something with the registers but I can not find it. Somebody did it work with a similar TFT? Can you give me a hint on what to look for?

Thank you.

Re: 5329 + TFT : flicker problem

cobratux — Mon, 19 Mar 2007 22:14:12 GMT

Hi nafiton,
are you using Linux as OS or trying the Freescale demo projects for CodeWarrior? The COBRA5329 Linux BSP V1.0 used a very slow pixel clock frequency because of the internal bus traffic on MCF5329. In the meanwhile there were done some optimizations (TFT controller priority on internal cross-bar switch, color depth etc.) so it's possible to speed up the pixel clock frequency to a much higher value. All "official" COBRA5329 demo software for VGA resolution is done by Emlix (www.emlix.com) and for Linux. Besides we changed to a QVGA display because this is typically requested by most COBRA5329 users.

Re: 5329 + TFT : flicker problem

nafiton — Sat, 31 Mar 2007 08:08:39 GMT

Hi cobratux.

We are working on uclinux. Changing the priority to maximum for the LCD controller solved that problem here. Thanks.