Graphic distortion when accessing SRAM?

Discussion created by lpcware Employee on Jun 15, 2016
Content originally posted in LPCWare by tjoAG on Tue Aug 07 22:39:34 MST 2012
Hi All

I'm using a LPC1788 at 120 MHz, with a 16 bit SDRAM and 16 bit SRAM

The frame buffer is located in the SDRAM and I use the SRAM for some persistent data.

When I access the SRAM with relative large memory amount (+300 bytes memcpy), the display has graphics distortion. It looks like it draws shadows of the text displayed.

I guess the EMC is busy accessing the SRAM and the LCD DMA transfer is blocked.

I could split my SRAM access into smaller pieces or use DMA access to the SRAM.
That may help?

Speed up SRAM/SDRAM timing?

But is there any other solutions or am I just doing things wrong.
I'm using FreeRTOS.