bug_id,bug_type,severity,buggy_snippet,fixed_snippet,description,fix_patch,verilog_ref,tool rtl_001,LATCH_INFERRED,WARNING,"always @(*) begin if (sel == 2'b00) out = a; else if (sel == 2'b01) out = b; end","always @(*) begin case (sel) 2'b00: out = a; 2'b01: out = b; default: out = '0; endcase end",Incomplete if-else in combinational always block infers latch on out,Replace if-else with case statement and add default branch,mux.v:12,OpenROAD rtl_002,MULTIDRIVEN_NET,WARNING,"assign net_reset_sync = rst_gen_out; assign net_reset_sync = por_cell_rst;",assign net_reset_sync = rst_gen_out | por_cell_rst;,Two concurrent assign statements drive the same net causing contention,Merge drivers using OR gate into single assign statement,reset_ctrl.v:15,OpenROAD rtl_003,TIMING_VIOLATION,ERROR,"always @(posedge clk) begin sum <= a + b + c + d + e + f; end","always @(posedge clk) begin stage1 <= a + b; stage2 <= c + d; stage3 <= e + f; end always @(posedge clk) begin sum <= stage1 + stage2 + stage3; end",Deep combinational path in single-cycle adder causes WNS violation,Pipeline the adder across two clock cycles using intermediate registers,adder.v:42,OpenROAD rtl_004,COMBINATIONAL_LOOP,ERROR,"assign grant = req & ~busy; assign busy = grant & processing;","always @(posedge clk) begin grant <= req & ~busy; end assign busy = grant & processing;",Combinational feedback loop: req->grant->busy->grant,Register the grant signal to break the combinational loop,scheduler.v:88,OpenROAD rtl_005,CLOCK_DOMAIN_CROSSING,WARNING,"always @(posedge clk_fast) begin data_out <= data_in_slow; end","reg data_sync1, data_sync2; always @(posedge clk_fast) begin data_sync1 <= data_in_slow; data_sync2 <= data_sync1; end assign data_out = data_sync2;",Direct sampling of slow-domain signal in fast-domain without synchronizer,Insert 2-flop synchronizer chain between clock domains,cdc_bridge.v:34,OpenROAD rtl_006,UNDRIVEN_PORT,WARNING,"module controller( input clk, input rst, input clk_en ); always @(posedge clk) begin if (!rst) state <= IDLE; end","module controller( input clk, input rst, input clk_en ); always @(posedge clk) begin if (!rst) state <= IDLE; else if (clk_en) state <= next_state; end",Input port clk_en declared but never used in logic,Use clk_en as clock enable condition in always block,controller.v:8,OpenROAD