yosys/tests/sim/sim_cycles.ys

read_verilog dff.v
prep

# create fst with 20 clock cycles (41 samples, 202ns)
sim -clock clk -fst sim_cycles.fst -width 2 -n 20

logger -expect-no-warnings

# final step is 41
logger -expect log "Co-simulating cycle 41" 2
logger -warn "Co-simulating cycle 42"
sim -clock clk -r sim_cycles.fst -scope dff -n 21 -sim-cmp
sim -clock clk -r sim_cycles.fst -scope dff -stop 41 -sim-cmp
logger -check-expected

# over limit stops at final step
logger -expect log "Co-simulating cycle 41" 2
sim -clock clk -r sim_cycles.fst -scope dff -n 30 -sim-cmp
# -stop warns for over limit
logger -nowarn "Stop time is after simulation file end time"
sim -clock clk -r sim_cycles.fst -scope dff -stop 50 -sim-cmp
logger -check-expected

# don't auto step last
logger -expect log "Co-simulating cycle 40" 2
logger -warn "Co-simulating cycle 41"
sim -clock clk -r sim_cycles.fst -scope dff -n 20 -sim-cmp
sim -clock clk -r sim_cycles.fst -scope dff -stop 40 -sim-cmp
logger -check-expected

# -n 10 == -stop 20
# should simulate up to 20 and not more
logger -expect log "Co-simulating cycle 20" 2
logger -warn "Co-simulating cycle 21"
sim -clock clk -r sim_cycles.fst -scope dff -n 10 -sim-cmp
sim -clock clk -r sim_cycles.fst -scope dff -stop 20 -sim-cmp
logger -check-expected

# -n 1 == -stop 2
logger -expect log "Co-simulating cycle 2" 2
logger -warn "Co-simulating cycle 3"
sim -clock clk -r sim_cycles.fst -scope dff -n 1 -sim-cmp
sim -clock clk -r sim_cycles.fst -scope dff -stop 2 -sim-cmp
logger -check-expected

# -n 0 == -stop 0
logger -expect log "Co-simulating cycle 0" 2
logger -warn "Co-simulating cycle 1"
sim -clock clk -r sim_cycles.fst -scope dff -n 0 -sim-cmp
sim -clock clk -r sim_cycles.fst -scope dff -stop 0 -sim-cmp
logger -check-expected