General Description: Synchronous FIFO v1_0 does not appear in the main Core Generator GUI, although I tried to select it by choosing Project -> Cores Catalog Display -> Customize. I cannot selected it to be displayed, so it cannot be generated at all.
When I go to the Cores Catalog Display -> Customize window and try to select the Synchronous FIFO v1_0 for the Virtex Family, the Synchronous FIFO v1_0 for the 4K Family is selected as well, but neither of them will appear in the main GUI. In addition, the core name sometimes appears a green color, then changes back to black.
This occurs because there are two versions of the Synchronous FIFO v1_0 core, one for the XC4000 family, and one for the Virtex/Virtex-II family. CORE Generator cannot distinguish which version to select, so neither one is selected.
If you are designing with the Virtex or Virtex-II family, use the latest version of the Synchronous FIFO, which is v2 or v3 and later. If you must use v1_0, then archive or rename the following directory (e.g., rename the directory "fifo" to "fifo_save_4k"):
Renaming the above directory will disable Synchronous FIFO v1_0 for the XC4000 family.
If you are designing with the XC4000 family and need to use Synchronous FIFO v1_0 (for 4K), then you will need to archive (rename) the Synchronous FIFO directory for the Virtex family. Rename the following directory (e.g., rename "sync_fifo_v1_0" to "sync_fifo_v1_0_save"):