The Option to use UltraRAM for Line Buffers is listed in (PG231), but it is not available in the GUI.
The UltraRAM utilization impact on LUTs and FIFOs is now higher due to changes in Vivado.
As a result, tool changes will be required before UltraRAM can be enabled in the HLS IPs.
Until these changes are made, it is not recommended to enable UltraRAM in HLS IPs.
The 'Use UltraRAM for Line Buffers' option is only available in Vivado versions up to 2018.3 and on some specific boards, as not all boards contain UltraRAM (Please see below for the list of devices).
Across all families (CG/EV/EG):