Simscope + Verilog

Simscope automatically groups errors into Signatures

Simscope captures all types of Verilog and SystemVerilog errors:

• Functional errors
  • Data/transaction/model mismatches
  • Scoreboard errors
  • Overflow/underflow
• Runtime errors
  • Assertions, coverage errors
  • Timing violations
  • Crashes/segfaults
  • Out of memory errors, disk errors
  • Timeouts
• Compile errors

Sample SystemVerilog error

ncsim: *E,TRNULLID: NULL pointer dereference.

Sample Verilog compile error

ncvlog: *E,INTOVF (test.v,17|34): bit overflow during conversion from text [2.5(IEEE)] (10 bits).

→ Signature #100:

ncvlog ... INTOVF test.v ... bit overflow during conversion from text ... IEEE ... bits

Sample Verilog assertions

ncsim: *E,ASRTST (syn_fifo_psl.v,108): (time 49 NS)     Assertion fifo_tb.fifo.ERROR_readempty has failed

→ Signature #1011:

ncsim ... ASRTST syn_fifo_psl.v ... time ... NS Assertion [HIER].ERROR_readempty has failed

Sample UVM errors

UVM_ERROR        @ 305412ps   [uvm_test_top.subsys2.ovc_ref_model.scoreboard]: wr:<0051> wr_data:[0x00000168] rd:5'b011x1 rd_data:[0x000003e5]

→ Signature #240:

UVM_ERROR ... [HIER].scoreboard wr ... wr_data ... rd ... rd_data ...

Sample UVM error

    if (tx_pkt.mac_dst_addr != rx_pkt.mac_dst_addr) begin
        `uvm_error(get_name(), $psprintf("MAC_DST_ADDR MISMATCH!, Exp=0x%0x, Act=0x%0x",
                                         tx_pkt.mac_dst_addr, rx_pkt.mac_dst_addr))
    end

Work on groups of errors, rather than each individual error.

Diagnostics

• Quickly see trends over time.
• See the first checkin to trigger the error.
• Break down by component and simulator.
• Sort by runtime or cycles, to find the shortest simulations.
• See who is working on it.
• Assign and open a bug on it.

Advanced analysis

• Analyze if specific plusargs are causing the error.

Rerun failures

For further debugging, users can easily rerun failures, with exact reproducibility:

• Model source version (checkin)
• Build target
• Simulator
• Config string/plusargs

Tracking PASS

Simscope also tracks passing simulations for analysis:

• See when the last time a test passed.
• View pass/fail rates.
• Track CPS and other performance.

Simulators

Simscope is simulator-independent:

• Synopsys VCS
• Cadence NCSim

More integrations