Vivado simulation crashes due to Verilog arrays defined in LSB format in cv32e40x_alignment_buffer.sv

[Srrbli-23]

Vivado simulation crashes due to Verilog arrays defined in LSB format in cv32e40x_alignment_buffer.sv

Component

Component:RTL
rtl/cv32e40x_alignment_buffer.sv

Steps to Reproduce

Git hash: v0.8.0 b22444c7f517964313286af485e4a4ddb62467cc https://github.com/openhwgroup/cv32e40x/commit/b22444c7f517964313286af485e4a4ddb62467cc

Hello,

As a beginner testing the cv32e40x project on Xilinx's FPGA, I found that the project includes the file cv32e40x_alignment_buffer.sv, which contains two arrays defined in LSB format. These arrays cause Vivado to crash during simulation.

  inst_resp_t [0:ALBUF_DEPTH-1]  resp_q;
  logic [0:ALBUF_DEPTH-1]        valid_n,   valid_int,   valid_q;

When running the simulation in Vivado, the following error message will be prompted, and the simulation will crash:

FATAL_ERROR: Vivado Simulator kernel has discovered an exceptional condition from which it cannot recover. Process will terminate. For technical support on this issue, please open a WebCase with this project attached at http://www.xilinx.com/support.
Time: 0 ps  Iteration: 0  Process: /path/to/u0/if_stage_i/prefetch_unit_i/alignment_buffer_i/NetRegassign166_292
  File: /path/to/cv32e40x_alignment_buffer.sv

To resolve this issue, it is recommended that the arrays be defined in MSB format, for example:

  inst_resp_t [ALBUF_DEPTH-1:0]  resp_q; 
  logic [ALBUF_DEPTH-1:0]        valid_n,   valid_int,   valid_q;

I believe this may be a Vivado simulation software issue. However, updating the arrays to be defined in MSB format can facilitate debugging on an FPGA.

Thanks!
Srrb

[Silabs-ArjanB]

Vivado issue should be worked around with #864