The internal software in most digital avalanche transceivers can be updated. This feature (pioneered by Pieps) allows you to update your beacon with new features without purchasing a new avalanche transceiver.
The Pieps DSP Sport and Pieps DSP Pro were designed to be user-updatable, but this feature (specifically, the cable that is used to update these devices via the headphone jack) was never released to the public. All of the newer Pieps and Black Diamond transceivers can be updating using a Bluetooth enabled Android or iOS device. The BCA Tracker3 is user-updatable using a USB cable (not so the Tracker S). The Mammut Barryvox transceivers can do device-to-device updates (e.g., your buddy can update your transceiver in the parking lot).
Other transceivers either can't be updated or require that you send your transceiver to a service center.
Learn about software updates to these transceivers: