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The USRP™ Hardware Driver Repository
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e320: Ensure consistent sequencing when powering on/off GPSDO #755

Closed draeman-synoptic closed 3 months ago

draeman-synoptic commented 3 months ago

Pull Request Details

When powering up the GPSDO, ensure the GPS_3V3 rail is up before taking the GPSDO out of reset. When powering down the GPSDO, ensure I/O signals are driven low to ensure GPSDO isn't backfed power via its I/O input pins.

It's worth noting that this PR doesn't address a specific issue, but rather is an improvement in behavior I noted when I was troubleshooting an unrelated GPSDO issue.

Which devices/areas does this affect?

Impacts MPM control of GPS power state on USRP E320 radios.

Testing Done

Confirmed that updated logic functions as expected, "e320_bist gpsdo" functions as expected on the radio, and GPSDO can be powered on and powered off as expected.

Checklist