Article ID: 000074523 Content Type: Troubleshooting Last Reviewed: 09/18/2013

Default tCCD for LPDDR2 Devices Hard Codes to 2 Cycles

Environment

  • Quartus® II Subscription Edition
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT

    Critical Issue

    Description

    This problem affects LPDDR2 products.

    This issue applies to LPDDR2 interfaces, when an LPDDR2-S2 memory device is used. Generated example designs always set tCCD=2 cycles for LPDDR2 devices, but the minimum tCCD supported for LPDDR2-S2 is 1 cycle. Having tCCD=1 for LPDDR2-S2 devices may impact design performance.

    Resolution

    The workarounds for this issue are described below.

    For designs using the High Performance Controller II (HPCII):

    1. In a text editor, open the file /dut_example_design/example_project/dut_example/submodules/ *_example_if0_c0.v.
    2. Search for .CFG_TCCD (2) and change it to .CFG_TCCD (1).

    For designs using the hard memory controller:

    1. In a text editor, open the file /dut_example_design/example_project/dut_example/submodules/ *_example_if0.v.
    2. Search for .ENUM_MEM_IF_TCCD (“TCCD_2”) and change it to .ENUM_MEM_IF_TCCD (“TCCD_1”).

    This issue will be fixed in a future version.

    Related Products

    This article applies to 2 products

    Arria® V FPGAs and SoC FPGAs
    Cyclone® V FPGAs and SoC FPGAs