Critical Issue
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.
The workarounds for this issue are described below.
For designs using the High Performance Controller II (HPCII):
- In a text editor, open the file
/dut_example_design/example_project/dut_example/submodules/ *_example_if0_c0.v
. - Search for
.CFG_TCCD (2)
and change it to.CFG_TCCD (1)
.
For designs using the hard memory controller:
- In a text editor, open the file
/dut_example_design/example_project/dut_example/submodules/ *_example_if0.v
. - 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.