Patent Publication Number: US-2010125726-A1

Title: Thin client host wakeup method and thin client host

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application Serial Number 97144930, filed Nov. 20, 2008, which is herein incorporated by reference. 
     BACKGROUND 
     1. Field of Invention 
     The present invention relates to a thin client host wakeup method. More particularly, the present invention relates to a thin client host wakeup method and a thin client host. 
     2. Description of Related Art 
     A thin client (sometimes also called a lean or slim client) is a client computer or client software in client-server architecture networks that depends primarily on the central server for processing activities, and mainly focuses on conveying input and output between the user and the remote server. Many thin client devices run only web browsers or remote desktop software, meaning that all significant processing occurs on the server and each thin client device doesn&#39;t comprise complicated modules. However, the thin client host is much more simple than a complete computer. Thus the thin client host doesn&#39;t have a power management system like advanced configuration and power Interface (ACPI) and can&#39;t deal with the switching mechanism between the sleep mode and active mode. 
     Thus, what is needed is a thin client host and a thin client host wakeup method to perform a wakeup mechanism on a thin client host to switch the thin client host from the sleep mode to the active mode. The present invention addresses such a need. 
     SUMMARY 
     A thin client host wakeup method is provided. A thin client host wakeup method switches a thin client host from a sleep mode back to an active mode, wherein the thin client host wakeup method comprises the steps of: receiving a wake on LAN packet to generate a wakeup interrupt; determining a storing module of the thin client host having a sleep flag; generating a trigger signal to the power module to activate the power module; electrically connecting the power module to a power switch; and retrieving a former system status and switching the thin client host from the sleep mode back to the active mode according to the former system status. 
     Another object of the present invention is to provide a thin client host having a sleep mode and an active mode, wherein the thin client host comprises: a storing module, a power module, a network module and a processing module. The storing module is to store a sleep flag during the sleep mode. The power module is to provide the power of the thin client during the active mode. The network module is to receive a wake on LAN (WOL) packet to generate a wakeup interrupt, and the processing module is to receive the wakeup interrupt to determine the storing module has the sleep flag and further generate a trigger signal to the power module to activate the power module and electrically connect the power module to a power switch, the processing module further retrieves a former system status and switches the thin client host from the sleep mode back to the active mode according to the former system status. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a block diagram of a thin client host of the first embodiment of the present invention; and 
         FIG. 2  is a flow chart of the thin client host wakeup method of the second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Please refer to  FIG. 1 , a block diagram of a thin client host  1  of the first embodiment of the present invention. The thin client host  1  has a sleep mode and an active mode, wherein the thin client host comprises: a storing module  100 , a power module  102 , a network module  104 , a power switch  106 , a processing module  108  and a system memory  110 . The processing module  108  is substantially a central processing unit. When the thin client host  1  is in the sleep mode, the peripheral devices (not shown) of the thin client host  1  will be shut down. The processing module  108  lowers the operating frequency as well to lower the electric power consumption. The storing module  100  is to store a sleep flag  101  and a former system status  103  during the sleep mode. The power module  102  is to provide the power of the thin client  1  during the active mode. The network module  104  in the present embodiment is a network interface controller to receive a wake on LAN (WOL) packet  105  to generate a wakeup interrupt  107 . The power switch  106  is electrically connected to the processing module  108  when the thin client host is in the sleep mode. After the processing module  108  receives the wakeup interrupt  107  generated by the network module  104 , the processing module  108  checks if the storing module  100  stores a sleep flag  101 . If the storing module  100  doesn&#39;t have the sleep flag  101 , the processing module  108  determines that the thin client host  1  is not in a sleep mode and turns on the system according to a normal boot process. If the storing module  100  has the sleep flag  101 , the processing module  108  determines that the thin client host  1  is in a sleep mode. 
     After making sure that the thin client host  1  is in a sleep mode, the processing module  108  further performs a wakeup process  109  and a power management process  111 . The wakeup process  109  and the power management process  111  are actually stored in the lowest address of the system memory  110  before the thin client host  1  enters the sleep mode. By storing the processes in the lowest address, the thin client host  1  can shut down the power of higher address part of the system memory  100  in the sleep mode. The processing module  108  transfer a trigger signal  113  to the power module  102  to activate the power module  102  according to the power management process  111  to supply the power of the thin client host  1  when it is back to the active mode. The processing module  108  further switches the power switch  106  from the processing module  108  to the power module  102 . Then, the processing module  108  retrieves the former system status  103  from the storing module  100  according to the wakeup process  109  to switch the thin client host  1  from the sleep mode back to the active mode according to the former system status  103 . 
     The power switch  106  is electrically connected to the power module  102  during the active mode and is electrically connected to the processing module  108  during the sleep mode. Thus, during the sleep mode, when the power switch  106  is triggered, the power switch  106  won&#39;t directly reset the power module  102  to reboot the system to avoid losing the former system status  103  stored in the storing module  100 . When the power switch  106  is triggered during sleep mode, the power switch  106  will send a wakeup interrupt  115  to the processing module  108  instead. The wakeup interrupt  115  and the wakeup interrupt  107  are substantially the same interrupt that will further perform the wakeup process  109  and the power management process  111  to switch the thin client host  1  back to the active mode. The processing module  108  retrieves the former system status  103  of the thin client host  1  according to the wakeup process  109 . The former system status  103  comprises the variables of the system and the data in the system memory  110  of the thin client host  1  before the thin client host  1  enters the sleep mode. The wakeup process  109  further restores the operation frequency of the processing module  108  and activates the power of the peripheral devices to restore the active mode. 
       FIG. 2  is a flow chart of the thin client host wakeup method of the second embodiment of the present invention. The thin client host wakeup method switches a thin client host as described in the first embodiment from a sleep mode back to an active mode, wherein the thin client host wakeup method comprises the steps of: in step  201 , receiving a wake on LAN packet to generate a wakeup interrupt; in step  202 , determining a storing module of the thin client host having a sleep flag; in step  203 , generating a trigger signal to the power module to activate the power module; in step  204 , electrically connecting the power module to a power switch; and in step  205 , retrieving a former system status and switching the thin client host from the sleep mode back to the active mode according to the former system status. 
     The thin client host and the thin client host wakeup method of the present invention receive the wake on LAN packet through the network module, and make the power switch switch between the power module and the processing module in different modes to simulate the wakeup process. The thin client thus doesn&#39;t need a complex power management system such as advanced configuration and power Interface (ACPI) to accomplish the wakeup mechanism. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.