some useful options for vcd converter, some docs

Makefile

@@ -38,7 +38,11 @@ jpeg_rtl_sim: $(JPEG_CORE_VVP)
 # picorv32 targets
 #
 
-picorv32_rtl_sim:
+test_vcd:
 	make -C picorv32 test_vcd
-	cp picorv32/testbench.vcd picorv32.vcd
 
+test_ez_vcd:
+	make -C picorv32 test_ez_vcd
+
+testbench.npy:
+	./picorv32_vcd_import.py picorv32/testbench.vcd testbench.npy

README.md

@@ -18,18 +18,33 @@ If `nix` is not installed, follow this [guide](https://librelane.readthedocs.io/
 ## Usage
 
 Compile jpeg decoder core using `iverilog` and run RTL simulation of the jpeg decoder core using `vvp`:
-
 ```
 nix develop
 make
 uv run jpeg_core_tb_run_plasma.py
 ```
+Call `uv run jpeg_core_tb_run_plasma.py --help` for more options.
 
 Load synthesized circuits and display statistics (example code):
-
 ```
 uv run load_sky130_circuits.py
 ```
 
-Works also outside a `nix develop` shell if [uv](https://docs.astral.sh/uv/) is installed on the base system. The script demonstrates how to obtain synthesized netlists via nix derivations [published in this github repository](https://github.com/s-holst/benchmark-circuits). These circuits along with layout and timings are built on-demand (using LibreLane) if not yet available in local nix store.
+Run picorv32's built-in testbench (generate `picorv32/testbench.vcd`):
+```
+make test_vcd
+```
+or
+```
+make test_ez_vcd
+```
+
+Import generated VCD with kyupy and convert it to a pattern file for later fault simulation:
+```
+uv run picorv32_vcd_import.py picorv32/testbench.vcd patterns.npy
+```
+Call `uv run picorv32_vcd_import.py --help` for more options.
+
+
+Some `uv` commands work also outside a `nix develop` shell if [uv](https://docs.astral.sh/uv/) is installed on the base system. The script demonstrates how to obtain synthesized netlists via nix derivations [published in this github repository](https://github.com/s-holst/benchmark-circuits). These circuits along with layout and timings are built on-demand (using LibreLane) if not yet available in local nix store.
 

picorv32_vcd_import.py

@@ -2,6 +2,8 @@
 
 import re
 import argparse
+from pathlib import Path
+
 import numpy as np
 from PIL import Image
 
@@ -10,6 +12,19 @@ from kyupy.techlib import SKY130
 from kyupy.logic_sim import LogicSim4V
 
 
+def path_for(circuit: str):
+    import subprocess
+    return Path(subprocess.check_output(
+        ["nix", "build", "--print-out-paths", "--no-link",
+         f"github:s-holst/benchmark-circuits#{circuit}" ],
+        text=True,
+    ).strip())
+
+
+def verilog_nl_path_for(circuit: str):
+    return next(path_for(circuit).glob("*/nl/*.nl.v"))
+
+
 def check_conflicts(patterns1, patterns2, names):
     conflicts = (patterns1 != patterns2) & (patterns1 != logic.UNKNOWN) & (patterns1 != logic.UNASSIGNED) & (patterns2 != logic.UNKNOWN) & (patterns2 != logic.UNASSIGNED)
     if conflicts.sum() > 0:
@@ -20,7 +35,7 @@ def check_conflicts(patterns1, patterns2, names):
     assert conflicts.sum() == 0, "incompatible patterns"
 
 
-def propagate_and_check(sim: LogicSim4V, patterns: np.ndarray, node2name: dict):
+def sim_and_check(sim: LogicSim4V, patterns: np.ndarray, node2name: dict):
     responses = np.full_like(patterns, logic.UNASSIGNED)
     sim.simulate(patterns, responses)
     #to_image(np.concatenate([patterns, responses]), 'pat_res.png')
@@ -61,15 +76,17 @@ def find_name(c, n):
 
 
 def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument('dut', type=str, help='verilog file with unit under test (uut)')
-    parser.add_argument('vcd', type=str, help='vcd file to process')
+    parser = argparse.ArgumentParser(description='Imports a VCD file from PicoRV32 simulation into kyupy, simulates a few cycles and save the patterns as npy file for later fault simulation.')
+    parser.add_argument('vcd', type=str, help='input vcd file')
+    parser.add_argument('npy', type=str, help='output pattern file in npy format')
+    parser.add_argument('-c', type=int, default=16, help='number of clock cycles to re-simulate for filling unknowns')
+    parser.add_argument('-n', type=int, default=0, help='number of patterns to convert (default 0=all)')
     args = parser.parse_args()
 
-    c = verilog.load(args.dut, tlib=SKY130)
+    c = verilog.load(verilog_nl_path_for("picorv32-sky130"), tlib=SKY130)
     log.info(f'circuit: {c}')
     c.resolve_tlib_cells(tlib=SKY130)
-    s_locs = {} #{n.name: l for l, n in enumerate(c.s_nodes)}
+    s_locs = {}
     name2node = {}
     node2name = {}
 
@@ -97,7 +114,7 @@ def main():
                     locs.append(-1)
             return locs
 
-    def var_locs_picorv(var: vcd.Var):
+    def var_locs(var: vcd.Var):
         if var.scope.name in ['uut', 'picorv32_core', 'pcpi_mul', 'pcpi_div']:
             if var.reference.startswith('cpu_state'):  # FSM got re-coded during synthesis
                 return []
@@ -122,13 +139,14 @@ def main():
         return []
 
     def step_filter(time, values, var_map):
-        clk_val = values[clk_loc]
-        return clk_val == 0 and time < 100e6
+        if args.n > 0 and time is not None and time >= (args.n*10000):
+            return False
+        return values[clk_loc] == 0
 
-    sim = LogicSim4V(c, sims=1024)
+    sim = LogicSim4V(c, sims=10240, c_reuse=True, strip_forks=True)
     log.info(f'sim: {sim}')
 
-    v = vcd.load(args.vcd, var_locs=var_locs_picorv, step_filter=step_filter, s_len=sim.s_len)
+    v = vcd.load(args.vcd, var_locs=var_locs, step_filter=step_filter, s_len=sim.s_len)
     log.info(f'vcd: {v}')
 
     unknown_pi = 0
@@ -146,12 +164,12 @@ def main():
     log.info(f'Total bits unassigned: {(v.data == logic.UNASSIGNED).sum()} unknown: {(v.data == logic.UNKNOWN).sum()}')
 
     merged = v.data
-    np.save('testbench_orig.npy', merged)
-    for i in range(30):
-        merged = propagate_and_check(sim, merged, node2name)
-        log.info(f'PropCycle[{i}] total bits unassigned: {(merged == logic.UNASSIGNED).sum()} unknown: {(merged == logic.UNKNOWN).sum()}')
+    for i in range(args.c):
+        merged = sim_and_check(sim, merged, node2name)
+        log.info(f'Cycle[{i}] total bits unassigned: {(merged == logic.UNASSIGNED).sum()} unknown: {(merged == logic.UNKNOWN).sum()}')
 
-    np.save('testbench_prop.npy', merged)
+    log.info(f'Writing {args.npy}')
+    np.save(args.npy, merged)
 
 
 if __name__ == "__main__":