SpiceServer

A gRPC service for executing SPICE circuit simulations via various simulators as subprocesses.

Overview

SpiceServer accepts gRPC requests containing SPICE netlists and executes them using the specified simulator (e.g., ngspice, Xyce, LTspice). Results are streamed back to the client in real-time.

Simulator support

Xyce

Prerequisites

• CMake 3.15 or higher
• C++17 compatible compiler
• gRPC and Protocol Buffers
• A SPICE simulator (ngspice, Xyce, etc.)

Installing Dependencies

On Ubuntu/Debian:

sudo apt-get update
sudo apt-get install -y cmake build-essential
sudo apt-get install -y libgrpc++-dev libprotobuf-dev protobuf-compiler-grpc

(UNTESTED) On macOS with Homebrew:

brew install cmake grpc protobuf

Building

mkdir build
cd build
cmake ..
make -j $(nproc)

Running

Start the server (with port set to 50051):

./spice_server --port=50051 --nofind_simulators --static_installs=../static_installs.pb.txt

You can provide override paths to the Python modules for vlsirtools and the Python VLSIR bindings with the --python_vlsir and --python_vlsirtools flags (see src/netlister.cc or --help).

Using the example Python client to submit VLSIR netlists

The testdata/cmos_inverter_hdl21 directory contains an example Hdl21 description of a basic CMOS inverter for the Sky130 PDK and a simple testbench to demonstrate it. Hdl21 can output a vlsir::spice::SimInput protobuf containing the testbench and design under test, which the example client can submit to the spice server:

cd example_client
PYTHONPATH=${HOME}/src/Hdl21::${HOME}/src/Hdl21/pdks/Sky130 ./client.py

Using the example Python client to submit Spice files

The testdata directory contains example netlists to run through simulators. For example, you can run Xyce on cmost_inverter by running:

cd testdata/cmost_inverter
/path/to/Xyce main.sp

Or you could have the spice_server run it for you by sending the test data to the server with the example python3 client.py. First generat the required protobufs:

cd example_client
./generate_protobufs.sh

Then:

1. changing the values in static_installs.pb.txt to suit your system;
2. running the server with the above comand; and
3. running the client on the testdata dir:

example_client/client.py testdata/cmos_inverter testdata/cmos_inverter/main.sp

Querying

~/go/bin/grpcurl -plaintext localhost:50051 list

netlisters

spice_server uses scripts in VLSIR's VlsirTools to convert VLSIR netlist protobufs to different netlist formats.

It does this by invoking the python scripts directly from within the C++ program. For now, the python scripts are pulled in directly from the vlsir_repo submodule in this repo. An alternative would to make them available as system-wide (or user-wide, or venv-wide) packages instead.