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eembc / energyrunner

The EEMBC EnergyRunner application framework for the MLPerf Tiny benchmark.
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An N6705 with more than 2 modules reports incorrect timestamps #24

Open petertorelli opened 2 years ago

petertorelli commented 2 years ago

It has been observed that when using two 6781 modules in a Keysight N6705 device, the energy trace is stretched out by 2x the IO Manager timestamps.

petertorelli commented 2 years ago

The default power-on value of each module sets DLOG to Voltage=True. The runner only uses two channels, and does not reset the DLOG values. This causes extra voltage samples to appear. Since the modules are off, this can be diagnosed by zooming into the chart until oscillations appear between the current uJ value and 0. The result: the timestamps are off by a factor of 1.33x or 2x (depending on 3 or 4 modules), and the energy is reduced due to the introduction of zero samples. Version 3.0.11 (unreleased) attempts to fix this. Until it is released, please comment here if you need a copy.

petertorelli commented 2 years ago

Fixed in version 3.1.0. Scheduled for release in Q4.