Actions
Forum Thread Details
  • State Not Answered
  • Replies 7 replies
  • Subscribers 324 subscribers
  • Views 1257 views
  • Users 0 members are here
Related

How to red DDR vs BRAM

quadzilla

This is another doubtlessly naive question.  I know that you can read the BRAM by using XBram_ReadReg() and a BRAM controller.  Also that XBram_ReadReg() basically amounts to using Xil_In32() to read a memory location.

Can we do something similar to read the DDR RAM, or are we always forced to use the routines in xaxidma_bdring.c?

Parents
  • 0

    If you are using DDR memory you are probably accessing large blocks of data.  Directly accessing the MIG DDR using pointers, etc will result in one transfer per call.  DDR, AXI and the MIG are designed to provide efficient bursts of contiguous address locations. The only way I have found to get efficient DDR access by using the DMA logic.  If you are running Linux on a Zynq you can use the xilinx xdma (or is it zdma?) to move data in and out of the DDR.

Reply
  • 0

    If you are using DDR memory you are probably accessing large blocks of data.  Directly accessing the MIG DDR using pointers, etc will result in one transfer per call.  DDR, AXI and the MIG are designed to provide efficient bursts of contiguous address locations. The only way I have found to get efficient DDR access by using the DMA logic.  If you are running Linux on a Zynq you can use the xilinx xdma (or is it zdma?) to move data in and out of the DDR.

Children
No Data