u-blox NORA-W2 Series, Hardware Integration Manual

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NORA-W2 series - Hardware integration manual
UBX-22005177 - R01 Module integration Page 10 of 61
C1 – Public
NORA-W2 series modules can be used to design solutions with top-grade security. Including
integrated cryptographic hardware accelerators, NORA-W2 modules feature secure boot
functionality that ensures that they can only be restarted with authenticated software.
2.3 System functions
2.3.1 Power modes
NORA-W2 series modules are power efficient devices capable of operating in power saving mode. The
following system power modes are available:
• Standby state – stops Wi-Fi until the EXPRESSLINK_WAKE pin is asserted, the time has elapsed,
or activity on AT UART port is detected.
•
Light sleep – reduces the supply voltage of the digital peripherals, most of the RAM and CPU, and
keeps them clock-gated. The device wakes up on optional timeout, EXPRESSLINK_WAKE pin, or
UART input.
• Deep sleep – powers off all digital peripherals, most of the RAM and CPU, and changes the clock
sources of these parts to the clock, APB_CLK. The device wakes up on optional timeout or
EXPRESSLINK_WAKE pin.
• Idle - No power savings. Device will wake up on optional timeout, EXPRESSLINK_WAKE pin or
UART input.
Toggling the
EXPRESSLINK_WAKE pin on NORA-W2 module when module is in light sleep or deep
sleep or idle mode, allows the module to enter active wake mode.
2.3.2 Module reset
NORA-W2 series modules can be reset (rebooted) in any of the following ways:
• RESET_N pin. Normally set high by an internal pull-up, a logical low state on this signal low causes
a “reset” of the module. RESET_N should be driven by an open drain, open collector, or contact
switch.
• EXPRESSLINK_RST. Similar reset on NORA-W2 modules can be asserted using software
AT
command.
2.4 Antenna integration
Antenna interfaces are different for each module variant in the NORA-W2 series. The modules
support either an internal antenna (NORA-W256AWS) or external/integrated antennas connected
through a dedicated antenna pin (NORA-W251AWS).
2.4.1 Antenna solutions
NORA-W2 series modules support three different antenna solutions:
• NORA-W251AWS has an antenna pin that can be used with either the integrated SMD chip
antenna or external antenna.
• NORA-W256AWS includes an internal PCB trace antenna which is specifically designed and
optimized for the NORA-W2 module. There is no need for an RF trace design on the host PCB which
means less effort is required in the test lab.