bag3_digital.measurement.stdcells.inv

Module Contents

Classes

InvMeas

A simple inverter measurement manager.
class bag3_digital.measurement.stdcells.inv.InvMeas(meas_specs: Mapping[str, Any], log_file: str, log_level: pybag.enum.LogLevel = LogLevel.DEBUG, precision: int = 6)[source]

Bases: bag.simulation.measure.MeasurementManager

A simple inverter measurement manager.

This class measures the input-output delay of an inverter, as well as the output rise/fall times. A rail-to-rail 50% duty-cycle square wave is used as the input. Average power is estimated using numpy.trapz.

Notes

The specification dictionary has the following entries in addition to the default ones:

sim_paramsMapping[str, float]

Required entries are listed below.

t_perfloat

The period of the input stimulus.

t_rffloat

The rise/fall time of the input.

c_loadfloat

The load capacitance at the output.

sim_envsSequence[str]

The sequence of corners/simulation environments to characterize over.

plotbool

Optional. True to plot time-domain waveforms for debug. Defaults to False.

commit()[source]

Commit changes to specs dictionary. Perform necessary initialization.

async async_measure_performance(name: str, sim_dir: pathlib.Path, sim_db: bag.simulation.cache.SimulationDB, dut: Optional[bag.simulation.cache.DesignInstance], harnesses: Optional[Sequence[bag.simulation.cache.DesignInstance]] = None) → Mapping[str, Any][source]

A coroutine that performs measurement.

Parameters:

  • name (str) – name of this measurement.

  • sim_dir (Path) – simulation directory.

  • sim_db (SimulationDB) – the simulation database object.

  • dut (Optional[DesignInstance]) – the DUT to measure.

  • harnesses (Optional[Sequence[DesignInstance]]) – the list of DUT and harnesses to measure.

Returns:

output – the measurement results.

Return type:

Mapping[str, Any]

async async_meas_pvt(name: str, sim_dir: pathlib.Path, sim_db: bag.simulation.cache.SimulationDB, dut: Optional[bag.simulation.cache.DesignInstance], harnesses: Optional[Sequence[bag.simulation.cache.DesignInstance]], sim_env: str) → Mapping[str, Union[numpy.ndarray, bag.simulation.data.SimData]][source]

A coroutine that performs measurement for one corner.

Parameters:

  • name (str) – Name of this measurement.

  • sim_dir (Path) – Simulation directory.

  • sim_db (SimulationDB) – The simulation database object.

  • dut (Optional[DesignInstance]) – The DUT to measure.

  • harnesses (Optional[Sequence[DesignInstance]]) – The list of DUT and harnesses to measure.

  • sim_env (str) – The simulation environment.

Returns:

output – The measurement results. Contains the following entries:

sim_dataSimData

The raw simulation data.

delay_risenp.ndarray

The input-to-output delay for a low to high transition at the output.

delay_fallnp.ndarray

The input-to-output delay for a high to low transition at the output.

trans_risenp.ndarray

The output rise time.

trans_fallnp.ndarray

The output fall time.

pwr_avgnp.ndarray

The average power dissipation.

Return type:

Mapping[str, Union[np.ndarray, SimData]]

static plot_results(results: Mapping[str, Any], plot_dir: pathlib.Path) → None[source]

Plots and saves time-domain waveforms into a PDF.

Parameters:

  • results (Mapping[str, Any]) – The measurement results.

  • plot_dir (Path) – The directory to save plots.