PCIe Simple DMA Example vs. DDR Reference design

Actually there are quite a few links since there are 3 PCIe designs that I've found given by Altera--one simple dma, one chained dma (both of which use on-fpga ram) and then there is the DDR reference design for PCIe dma. The latter comes preloaded on the PCIe Stratix II GX Board, so yes, I would say there is quite a large link between PCIe and DDR.