BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of an indicating circuit for indicating network status in accordance with a preferred embodiment of the present invention, the indicating circuit includes a logic circuit;
FIG. 2 is a circuit diagram of an alternative logic circuit of the indicating circuit of FIG. 1;
FIG. 3 is a circuit diagram of another alternative logic circuit of the indicating circuit of FIG. 1;
FIG. 4 is a circuit diagram of a conventional indicating circuit employing the combination of two status signals; and
FIG. 5 is a circuit diagram of a conventional indicating circuit employing two signals independent from each other.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an indicating circuit for indicating network status in accordance with a preferred embodiment of the present invention is shown. The indicating circuit includes a signal-generating unit 100 in a kernel board, and an indicator circuit 200 in a device board. The signal-generating unit 100 includes a second type of network IC 120 for generating two signals independent from each other, a logic circuit 130 with two input terminals designated 2 and 3 and an output terminal designated 1, a micro controller unit (MCU) 110 for transmitting a network transmitting signal designated Speed from the network IC 120. The indicator circuit 200 includes a NOT gate U10, a first LED L10, a second LED L20, and a resistor Rd. The two input terminals 2 and 3 of the logic circuit 130 are respectively connected to a 10M/LINK/ACTIVITY pin and a 100M/LINK/ACTIVITY pin of the network IC 120. An input terminal of the NOT gate U10 and an anode of the first LED L10 receive the network transmitting signal Speed. An output terminal of the NOT gate U10 is connected to an anode of the second LED L20. The output terminal 1 of the logic circuit 130 is connected to a node B between cathodes of the two LEDs L10, L20 via the resistor Rd. The MCU 110 of the signal-generating unit 100 receives the network transmitting signal Speed from the network IC 120, and transmits the signal Speed to the input terminal of the NOT gate U10 and the anode of the first LED L10. The logic circuit 130 in this embodiment is a NOR gate. The logic circuit 130 outputs a signal designated Link according to the level/value at the output pins 10M/LINK/ACTIVITY and 100M/LINK/ACTIVITY. Table 3 shows level/value of the signal Link corresponding to the level/value at the output pins 10M/LINK/ACTIVITY and 100M/LINK/ACTIVITY.
TABLE 3
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Pins
Level/value
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10M/LINK/ACTIVITY
High/1
Low/0
Low/0
High/1
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100M/LINK/ACTIVITY
Low/0
High/1
Low/0
High/1
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Link
Low/0
Low/0
High/1
N/A
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When the network transmitting speed is 10 Mbps, the value of the signal Speed is High/1, and when the network transmitting speed is 100 Mbps, the value of the signal Speed is Low/0. When the value of the signal Speed is High/1 and the signal Link is Low/0, which occurs when the 10M/LINK/ACTIVITY pin is 1, the first LED L10 lights up. When the signal Speed is Low/0 and the value of the signal Link is Low/0, which occurs when the 100M/LINK/ACTIVITY pin is 1, the second LED L20 lights up. During transmission and receiving, at either speed, the corresponding LED L10, L20 blinks. When the 10M/LINK/ACTIVITY pin and 100M/LINK/ACTIVITY pin are both 0, causing the signal Link to go to 1, the first and second LEDs L10 and L20 remain off.
Referring to FIG. 2, the logic circuit 130 in accordance with a preferred embodiment of the indicating circuit includes a power supply source Vcc, a first NPN transistor Qa, a second NPN transistor Qb, and a resistor Re. Bases of the first transistor Qa and the second transistor Qb are used as the input terminals 2 and 3 of the logic circuit 130, the two input terminals 2 and 3 are respectively connected to the 10M/LINK/ACTIVITY pin and 100M/LINK/ACTIVITY pin of the network IC 120; a collector of the first transistor Qa is connected to the power supply source Vcc through the resistor Re; emitters of the first transistor Qa and the second transistor Qb are all grounded. The collector of the first transistor Qa and a collector of the second transistor Qb are connected together as the output terminal 1 of the logic circuit 130.
Referring to FIG. 3, the logic circuit 130a in accordance with an alternative embodiment of the indicating circuit includes a power supply source Vcc, a first N-channel metal-oxide-semiconductor field-effect transistor (MOSFET) Qc, a second N-channel MOSFET Qd, and a resistor Rf. Gates of the first and second MOSFETs Qc and Qd are used as the input terminals 2 and 3 of the logic circuit 130a, the two input terminals 2 and 3 are respectively connected to the 10M/LINK/ACTIVITY pin and 100M/LINK/ACTIVITY pin of the network IC 120; a drain of the first MOSFET Qc is connected to the power supply source Vcc through the resistor Rf; sources of the first and second MOSFETs Qc and Qd are all grounded. The drain of the first MOSFET Qc and a drain of the second MOSFET Qd are connected together as the output terminal 1 of the logic circuit 130a.
By adding the logic circuit 130 and the MCU 110 between the network IC 120 and the indicator circuit 200 in the kernel board, the indicator circuit 200 in the device board, which is directly compatible with the first type of network IC 10 as shown in FIG. 4, is also compatible with the second type of network IC 30 as shown in FIG. 5. So when specifications of customer orders for the kernel boards change, the device board has no need to be redesigned and tested, which saves costs and time.
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.
Patent Application
20080091400
