FIXED. It is no longer a gamble to use incremental flow in 2020.2. 2. The Fix: Vivado Simulator (XSIM) SystemVerilog Stability (CR-1058923) The Problem (2020.1): If your testbench used packed structs , unions , or complex interface modports, XSIM would frequently crash with Internal Error: xvcs.exe : *** Fatal Error: Segmentation Fault .
FIXED. The PR flow in 2020.2 is considered the most stable since Vivado 2019.2. 5. The Fix: GUI Performance on Linux (RHEL/CentOS 8) (CR-1082103) The Problem (2020.1): On Red Hat Enterprise Linux 8 and CentOS 8, the Vivado IDE would have a 2-5 second lag when opening the IP Catalog or the TCL Console. This was traced to bad interaction with the GTK3 theme engine. xilinx vivado 20202 fixed
FIXED. But note: You must run vivado -noextendedgl for best results, even in 2020.2. What Was NOT Fixed in Vivado 2020.2 (The Persistent Gripes) No article on "what was fixed" is honest without mentioning what remains broken. Vivado 2020.2 is better, but it is not perfect. The HLS Dataflow Bug Vivado HLS 2020.2 still contains a critical bug where #pragma HLS dataflow with multiple producer-consumer tasks can deadlock if one task uses a stream with depth > 1. The fix requires manually inserting #pragma HLS stable . This was not addressed until 2021.1. UltraScale+ Bitstream Generation Time Place & Route is faster, but bitstream generation ( write_bitstream ) on UltraScale+ devices (VU9P, ZU19EG) still takes 45-60 minutes for large designs. No change from 2020.1. Remote Host Mode (RHEL/CentOS 7) If you use remote_host to distribute compile jobs across a Linux farm, 2020.2 still occasionally loses file handles over NFS. The workaround (mounting with noac ) is still required. Step-by-Step: How to "Fix" Common 2020.2 Installation Issues Even with the fixes in 2020.2, installation can be tricky. Here is a community-sourced checklist to ensure your environment is robust. Step 1: The "No Licenses Found" Fix Issue: After install, Vivado claims no licenses exist, even with a valid .lic file. Fix in 2020.2: 2020.2 fixes this.
The EDIF parser in 2020.1 was case-sensitive incorrectly. 2020.2 fixes this. Vivado claims no licenses exist