Computer sleep/awake circuit

The present invention relates to a sleep/awake circuit, and more particularly to a circuit for automatically setting a sleep/awake state of a computer.

With the rapid development of personal computers, development of high performance components of a computer have brought about a corresponding increase in power use. Therefore wasting of power becomes more likely if the computer is not changed to a power saving state when not in use.

Typically, a sleep/awake circuit is made in designing computer power management for solving the above problem. There is usually a sleep/awake button on a keyboard of a computer that is connected to the inner sleep/awake circuit of a motherboard of the computer. The button is pressed by a user for putting the computer to sleep. Then when the user wishes, presses the same button again to awaken the computer.

However, the user may forget to press the button when the computer is not needed in a waking mode. Then power is wasted, and costs of operating the computer are increased for the user.

What is desired, therefore, is a sleep/awake circuit for automatically changing a sleep/awake state of a computer whenever needed.

In one preferred embodiment, a computer automatic sleep/awake circuit includes an infrared receiving/sending module, a micro-control circuit, and a bus control circuit. The micro-control circuit sends a command signal to the infrared receiving/sending module at predetermined intervals. The infrared receiving/sending module detects the presence or absence of a user and then sends a signal back to the micro-control circuit indicating a result. According to the result, the micro-control circuit exchanges data and clock signals with the bus control circuit. The bus control circuit then sends control signals to the computer to control sleep/awake states of the computer.

Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of a computer sleep/awake circuit in accordance with a preferred embodiment of the present invention; and

FIG. 2 is a circuit diagram of the computer sleep/awake circuit of FIG. 1 .

Referring to FIGS. 1 and 2 , a computer sleep/awake circuit of a preferred embodiment of the present invention includes an infrared receiving/sending (IR) module U 1 , a micro-control circuit 120 , a bus control circuit 140 , and a connection port 160 . The IR module U 1 first receives a command signal sent by the micro-control circuit 120 at certain intervals to detect presence or absence at an operation position of a user of an electronic device like a computer, and then sends a result to the micro-control circuit 120 . According to the result, the micro-control circuit 120 exchanges data and clock signals with the bus control circuit 140 . The bus control circuit 140 is electrically connected to a USB port of the computer via the connection port 160 for controlling sleep/awake states of the computer.

The IR module U 1 may be any one of a suitable IR device that is Infrared Data Association (IrDA) compliant and connectable to the computer, for detecting a human presence and is positioned on or about the computer so that it may detect a presence or absence of the user. In this embodiment the IR module has six connection pins 1 , 3 , 4 , 5 , 6 , 8 . Pin 8 is coupled to a system voltage VCC via a resistor R 1 . Pin 3 is connected to the system voltage VCC. Pins 1 and 5 are grounded.

The micro-control circuit 120 includes a micro controller unit (MCU) U 2 and a serial program interface J 1 . In the preferred embodiment of the present invention, the MCU U 2 is an AT89S51 produced by ATMEL Corporation. Pins 1 , 2 of the serial program interface J 1 are respectively connected to input/output pins 6 , 7 of the MCU U 2 . An input pin 8 of the MCU U 2 is coupled to a pin 3 of the serial program interface J 1 . A reset pin 9 of the MCU U 2 is connected to a pin 4 of the serial program interface J 1 . Sleep/awake control programs for the computer are written to the MCU U 2 via the serial program interface J 1 . A pin 10 of the MCU U 2 is connected to pin 4 of the IR module U 1 for receiving the result signals sent back by the IR module U 1 . A pin 11 of the MCU U 2 is connected to pin 6 of the IR module U 1 for sending command signals to the IR module U 1 . According to the command signals, the IR module U 1 emits infrared signals at certain intervals for detecting the presence or the absence of the user. A power pin 40 of the MCU U 2 is connected to the VCC. An earth pin 20 of the MCU U 2 is grounded.

The bus control circuit 140 includes a bus controller U 3 and a clock circuit 150 . In the preferred embodiment of the present invention, the bus controller U 3 is a universal serial bus (USB) controller PDIUSBD12 produced by the Philips Corporation. Data pins 1 to 4 , and 6 to 9 of the bus controller U 3 are connected to data pins 39 to 32 of the MCU U 2 respectively. A pin 10 of the bus controller U 3 is connected to a pin 30 of the MCU U 2 . A pin 11 of the bus controller U 3 is connected to a pin 28 of the MCU U 2 . Data exchange occurs between the bus controller U 3 and the MCU U 2 when the pin 28 of the MCU U 2 is at a low level. A suspend pin 12 is coupled to a pin 27 of the MCU U 2 . The bus controller U 3 is made inactive after a corresponding signal sent by the MCU U 2 when the bus is idle for a predetermined interval. An output clock pin 13 of the bus controller U 3 is connected to an input clock pin 19 of the MCU U 2 for providing clock signals to the MCU U 2 . An interrupt pin 14 of the bus controller U 3 is connected to an interrupt pin 12 of the MCU U 2 . A pin 28 of the bus controller U 3 is coupled to a pin 1 of the MCU U 2 , and is grounded via a resistor R 3 . Power pins 24 , 27 of the bus controller U 3 are connected to the VCC. A reset pin 20 of the bus controller U 3 is connected to a pin 21 of the MCU U 2 . The bus indicator light pin 21 is connected to a cathode of an LED D 1 . An anode of the LED D 1 is connected to the VCC. Pins 18 , 19 of the bus controller U 3 are coupled to the VCC. Read (RE-N), write (WR-N) pins 15 , 16 of the bus controller U 3 are respectively connected to pins 17 , 16 of the MCU U 2 . An earth pin 5 of the bus controller U 3 is grounded.

The clock circuit 150 includes a Crystal Oscillator (CO) X 1 , and two capacitors C 2 , C 3 . One end of each capacitor C 2 and C 3 is grounded. The other end of the capacitor C 2 is connected to a terminal 2 of the CO X 1 and an input clock pin 22 of the bus controller U 3 simultaneously, and the other end of the capacitor C 3 is connected to a terminal 1 of the CO X 1 and another input clock pin 23 of the bus controller U 3 simultaneously. The clock circuit 150 provides clock signals for the bus controller U 3 .

In the preferred embodiment, the sleep/awake circuit is formed in a separate enclosure with the connection port 160 USB port compatible. In other embodiments, the sleep/awake circuit may be incorporated on a circuit board of the computer.

The connection port 160 is connected to a USB port of the computer. A power pin 5 of the connection port 160 is connected to the VCC. Earth pins 1 , 2 of the connection port 160 are grounded. Data pins 4 , 3 of the connection port 160 are connected to bus data output pins 26 , 25 of the bus controller U 3 respectively. When the computer detects and accepts the connection with the sleep/awake circuit the LED D 1 will light.

According to the program, the MCU U 2 sends command signals to the IR module U 1 at certain intervals. The IR module U 1 then emits infrared signals directed at a space that would normally be occupied by the user when at the computer. If the IR module U 1 fails to receive reflected signals, then the user of the computer has left, and a user absent result signal is sent to the MCU U 2 by the IR module U 1 . The MCU U 2 then sends signals to activate the bus controller U 3 and command the bus controller U 3 to put the computer in a sleep state. The bus controller U 3 via the connection port 160 activates the sleep state of the computer. The bus controller U 3 then sends a signal to the MCU U 2 indicating the computer is in the sleep state. The MCU U 2 then sends a reset signal to reset the bus controller U 3 , and the bus controller U 3 then becomes inactive after resetting. At the same time, the infrared detecting process continues. When the presence of the user is detected by the IR module U 1 receiving reflected signals, the IR module U 1 sends a user present signal to the MCU U 2 . The MCU U 2 then sends signals to activate the bus controller U 3 and command the bus controller U 3 to put the computer in an awake state. The bus controller U 3 via the connection port 160 activates the awake state of the computer. The bus controller U 3 then sends a signal to the MCU U 2 indicating the computer is in the awake state. The MCU U 2 then sends a reset signal to reset the bus controller U 3 , and the bus controller U 3 then becomes inactive after resetting. The computer is thus automatically awakened.

The circuit further includes a manual reset switch circuit 100 for manual resetting the circuit when needed. The manual reset switch circuit 100 includes a manual button S 1 , a capacitor C 1 , and a resistor R 2 . The manual button S 1 parallel connected with the capacitor C 1 , and then both are placed between the VCC that is connected to a terminal 1 of the manual button S 1 and one end of the resistor R 2 . The other end of the resistor R 2 is grounded. The reset pin 9 of the MCU U 2 is connected to a terminal 2 of the manual button S 1 . In the using of the USB equipment, manual reset is needed to make the USB equipment to recover the normal working states when reset by the program of the MCU U 2 fails.

It is to be understood, however, that even though numerous characteristics and advantages of the preferred embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, equivalent material and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.