Product Info

LTE Standard Module Series
EC25 Series Hardware Design
EC25_Series_Hardware_Design 69 / 134
URC can be outputted from UART port, USB AT port and USB modem port through configuration via
AT+QURCCFG command. The default port is USB AT port.
In addition, RI behavior can be configured flexibly. The default behaviors of the RI is shown as below.
Table 23: Behaviors of RI
The RI behavior can be changed by AT+QCFG="urc/ri/ring" command. Please refer to document [2]
for details.
3.20. USB_BOOT Interface
EC25 provides a USB_BOOT pin. Customers can pull up USB_BOOT to 1.8 V before VDD_EXT is
powered up, and the module will enter emergency download mode when it is powered on. In this mode,
the module supports firmware upgrade over USB interface.
Table 24: Pin Definition of USB_BOOT Interface
The following figure shows a reference circuit of USB_BOOT interface.
State
Response
Idle
RI keeps at high level
URC
RI outputs 120 ms low pulse when a new URC returns
Pin Name
Pin No.
I/O
Description
Comment
USB_BOOT
115
DI
Force the module to enter emergency
download mode
1.8 V power domain.
Active high.
It is recommended to
reserve test points.
NOTE