LPC18xx LCD Controller SDRAM with DMA

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by MX21 on Fri Feb 12 11:03:02 MST 2016
I'm using the LCD Controller in the LPC1857 to run a TFT display.  We have an SDRAM connected to the EMC for the display memory.

I'm testing DMA to transfer the memory from SRAM to SDRAM.  When I do this, the display appears to lose sync during the DMA transfer.  As soon as the DMA is complete, the display is good and has the data I transferred.

Is there some conflict between the LCD Controller and the DMA when accessing SDRAM over EMC?  It seems the LCD Controller is not getting it's data properly when DMA is accessing the same memory.

If I just memcpy the data, it all looks clean.