User's Guide

LE920A4 HW User Guide Application Guide
Doc#: 1VV0301261 Antenna Detection
Rev. 4.7.1 Page 106 of 124 2019-11-21
11.5.2. Recovery Boot Mode
A Recovery Boot Download mode is used if a corrupted boot image was flashed into the
device or if all other recovery modes failed.
Recovery Boot Download mode is triggered by the WCI_RX signal (PAD AT2). Asserting
this signal high (1.8V) during boot will force the system into Recovery Boot Download
mode.
NOTE:
The application board must support accessible test pads on the GPIO_20
and WCI_RX signals to enable the download recovery modes mentioned
above.
Antenna Detection
The module provides an antenna detection application, indicating for each of the cellular
and GNSS antennas whether it is shorted to ground or open.
Refer to Ref 8: High-Speed Inter-Chip USB Electrical Specification, version 1.0
.
NOTE:
The antenna detection circuit is not presented inside the module but has to
be implemented externally following the guidance in the application note.