When using the xps_mch_emc core, the spacing between writes is too short, violating the back-to-back write timing specifications (tWPH).
This issue potentially affects flash devices when the xps_mch_emc is configured to use data width matching, and software performs accesses wider than the aggregate data width of all flash devices used. For example, a 32-bit access to a 16-bit flash will cause data width matching.
A patch is available to guard against violating tWPH. It can be downloaded from:
The patch adds an additional timing parameter for each memory bank: C_TWPH_PS_MEM_0, C_TWPH_PS_MEM_1, C_TWPH_PS_MEM_2, and C_TWPH_PS_MEM_3.
1. Extract the archive to a temporary folder.
2. Copy the contents of the archive to the <Project>\pcores folder.
3. Restart XPS.
Update the C_TWPH_PS_MEM_x parameter in the MHS for the associated memory. C_TWPH_PS_MEM_x defines the delay between writes in picoseconds (ps). Rebuild the netlist.
The XPS_MCH_EMC core is currently not planned to be updated with this enhancement.