Host Woken Up By Module - Huawei ME909u-523 Application Manual

HUAWEI ME909u-523 LTE LGA Module
Application Guide

8.3.5 Host Woken up by Module

Wake-up Source
A wake-up source is a module event that can wake up the host, for example, an
incoming voice call, a text message, data (PPP data, TCP/UDP data from the
network), and unsolicited messages.
Remotely Waking up the Host Using USB
When the host is in sleep mode and the USB controller is in suspended mode, if the
module needs to send data to the host (for example, a wake-up source has arrived),
the module sends a remote wake-up signal that lasts 3 ms to inform the host to start
USB resume (as shown in Figure 8-7 ). To complete the procedure, the following
conditions must be met:
1.
2.
3.
Figure 8-7 USB resume time sequence
Issue 04 (2014-12-08)
The USB controller on the host supports USB remote wake-up and can wake up
the host.
The USB driver enables or disables remote wake-up by executing
SET_FEATURE and CLEAR_FEATURE commands. Therefore, remote wake-up
must be enabled on the USB driver before USB enters suspended mode.
When the host receives the remote wake-up signal from the module, the host
needs to send a full speed K signal that lasts at least 20 ms. When the USB
controller resumes, the host must send the SOF token within 3 ms from the
startup of the idle state. Otherwise, the module enters suspended mode again,
as shown in Figure 8-7 .
Signaling
Start of
Resume
Signaling
D+
FS idle
D-
Start of
Resume
Signaling
3ms
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Sleeping and Waking Up Application Scenarios
Signaling
>20ms
FSK
if remote
wake up
<1.33us
<3.0ms
HS idle uSOF
Device
Device sees
Resumed
first activity
59