PS2 and IIC touch panel selection circuit on portable computer mainboard

Abstract

The utility model relates to a PS2 and IIC touch panel selection circuit on a portable computer mainboard. The PS2 and IIC touchpad selection circuit on the portable computer mainboard comprises a four-channel SPDT switch and a touchpad connector supporting connection with a PS2 touchpad and an IIC touchpad, wherein the four-channel SPDT switch is connected with the PS2 touchpad and the IIC touchpad; the four-channel SPDT switch comprises a first group of four-channel pins electrically connected with the touchpad connector, a second group of four-channel pins based on PS2 signal communication, a third group of four-channel pins based on IIC signal communication, and a selection pin; and the four-channel SPDT switch selectively connects the second group of four-channel pins or the third group of four-channel pins with the first group of four-channel pins according to the high level or the low level input into the selection pins. According to the PS2 and IIC touchpad selection circuit on the portable computer mainboard, the PS2 and IIC touchpads can be simultaneously supported by the same mainboard design through simple circuit design.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic computers, in particular to a PS2 and IIC touchpad selection circuit on a portable computer mainboard. Background Art

[0002] A portable computer is a personal computer with a small size, light weight, and convenient to carry. Its aliases include notebook computer, laptop, handheld computer, laptop computer, etc. The main feature of a portable computer is its portability, which enables users to use it at home, in the office, or anywhere, supporting mobile office within a short time. Despite its small size, the performance and functions of a portable computer are comparable to those of a traditional desktop computer, and it can handle various tasks, such as processing documents, editing videos, playing games, etc. In addition, a portable computer is usually equipped with a rechargeable battery and can be used for a long time without being plugged in, which is very useful when working outside the office or traveling.

[0003] A touchpad (TouchPad or TrackPad) can be regarded as a substitute for a mouse and is an input device widely used on portable devices. It controls the movement of the pointer by sensing the movement of the user's finger.

[0004] PS2 and IIC are two different communication protocols. The touchpad on a portable computer generally uses one of the two communication protocols, PS2 and IIC. If the portable computer manufacturer wants to replace the touchpad with another communication protocol after mass-producing the mainboard, they need to consider changing the mainboard circuit or reworking, etc., which will waste a lot of manpower and material resources. Summary of the Invention

[0005] Therefore, the purpose of the utility model is to provide a PS2 and IIC touchpad selection circuit on a portable computer mainboard to solve the problem that the existing mainboard cannot support both PS2 and IIC touchpads.

[0006] To achieve the above purpose, the utility model provides a PS2 and IIC touchpad selection circuit on a portable computer mainboard, including: a four-channel SPDT switch, and a touchpad connector supporting connection with a PS2 touchpad and an IIC touchpad; the four-channel SPDT switch includes a first group of four-channel pins electrically connected to the touchpad connector, a second group of four-channel pins for communicating based on PS2 signals, a third group of four-channel pins for communicating based on IIC signals, and a selection pin; the four-channel SPDT switch selects to connect the second group of four-channel pins or the third group of four-channel pins to the first group of four-channel pins according to whether the level input to the selection pin is high or low.

[0007] Among them, the selection pin is electrically connected to the GPIO pin of the CPU to input a selection signal from the CPU.

[0008] Among them, the EC is the chip IT8637.

[0009] Among them, the CPU is Feiteng D3000.

[0010] Among them, the second group of four-channel pins is electrically connected to the EC.

[0011] Among them, the third group of four-channel pins is electrically connected to the EC.

[0012] Among the four pins included in the third group of four-channel pins, two pins are electrically connected to the EC, and the other two pins are electrically connected to the CPU or the PCH.

[0013] Among them, the four-channel SPDT switch is the chip RS2233YTSS16.

[0014] Among them, the 12th, 9th, 7th, and 4th pins of the chip RS2233YTSS16 are electrically connected to the corresponding pins of the touch panel connector as the first group of four-channel pins.

[0015] Among them, the 13th, 10th, 6th, and 3rd pins of the chip RS2233YTSS16 are used as the second group of four-channel pins.

[0016] Among them, the 14th, 11th, 5th, and 2nd pins of the chip RS2233YTSS16 are used as the third group of four-channel pins.

[0017] Among them, the 16th pin of the chip RS2233YTSS16 is electrically connected to the 3.3V standby power supply on the main board.

[0018] In summary, for the PS2 and IIC touch panel selection circuit on the main board of the portable computer of the present invention, by means of a simple circuit design, the same main board design can support both PS2 and IIC touch panels at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following will, with reference to the drawings, make the technical solutions and other beneficial effects of the present invention obvious through a detailed description of the specific embodiments of the present invention. In the drawings,

[0020] Figure 1 is a schematic diagram of the principle of a preferred embodiment of the PS2 and IIC touch panel selection circuit on the main board of the portable computer of the present invention;

[0021] Figure 2Schematic diagram of the pin connection of a four-channel SPDT switch in a preferred embodiment of the PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present utility model;

[0022] Figure 3 Schematic diagram of the pin connection of the touchpad connector in a preferred embodiment of the PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present utility model. Detailed implementation manners

[0023] Refer to Figure 1 , which is a schematic diagram of the principle of a preferred embodiment of the PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present utility model, showing the main connection relationship of the circuit of the present utility model from the working principle. The PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present utility model mainly includes: a four-channel SPDT switch, and a touchpad connector supporting connection with a PS2 touchpad and an IIC touchpad. The existing solution of supporting a PS2 or IIC touchpad separately by devices such as the EC, PCH, and CPU on the motherboard of a portable computer is well known to those skilled in the art and will not be elaborated here. By using a four-channel SPDT switch, the present utility model enables the motherboard to support both IIC and PS2 touchpads simultaneously without other modifications.

[0024] In this preferred embodiment, the four-channel SPDT switch includes a first set of four-channel pins electrically connected to the touchpad connector, a second set of four-channel pins electrically connected to the EC for communicating based on PS2 signals, that is, it is preset that the EC drives the PS2 touchpad under the PS2 protocol, a third set of four-channel pins electrically connected to the CPU for communicating based on IIC signals, that is, it is preset that the CPU drives the IIC touchpad under the IIC protocol, and a selection pin; the four-channel SPDT switch selects to connect the second set of four-channel pins or the third set of four-channel pins to the first set of four-channel pins according to whether the level input to the selection pin is high or low.

[0025] Among them, the selection pin is electrically connected to the GPIO pin of the CPU to input a selection signal from the CPU. Thus, by the high or low level of the CPIO signal from the CPU, the IIC signal channel or the PS2 signal channel can be selected to connect to the touchpad connector, so that the motherboard adopting the circuit of the present utility model can support both PS2 and IIC touchpads simultaneously.

[0026] In this preferred embodiment, the CPU is electrically connected to a four-channel SPDT switch, and the IIC signal for driving the IIC touchpad comes from the CPU; in fact, according to the devices that may be used to drive the IIC touchpad pre-designed in the computer system, there are also various connection methods. For example, the IIC touchpad is driven by the IIC signal from the EC, or the IIC touchpad is driven by the IIC signal from the PCH, and so on.

[0027] See Figure 2 and Figure 3 , Figure 2 FIG. is a schematic diagram of the pin wiring of the four-channel SPDT switch in a preferred embodiment of the PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present invention. Figure 3 FIG. is a schematic diagram of the pin wiring of the touchpad connector in this preferred embodiment. In this preferred embodiment, the EC is the chip IT8637 produced by the manufacturer ITE, the CPU is the Feiteng D3000, and the four-channel SPDT switch specifically uses the chip RS2233YTSS16.

[0028] In this preferred embodiment, pins 12, 9, 7, and 4 of the chip RS2233YTSS16 are electrically connected to the corresponding pins of the touchpad connector as the first group of four-channel pins, and then group A signals can be transmitted between the touchpad connected to the touchpad connector.

[0029] In this preferred embodiment, pins 13, 10, 6, and 3 of the chip RS2233YTSS16 are electrically connected to the corresponding pins of the EC as the second group of four-channel pins, thus establishing a PS2 signal channel based on group B2 signals. Group B2 signals are based on the PS2 protocol, where the PS2CLK and PS2DATA signals control the sliding control of the touchpad, and the TPLEFT / RIGHT signals control the left and right buttons on the touchpad.

[0030] In this preferred embodiment, pins 14, 11, 5, and 2 of the chip RS2233YTSS16 are electrically connected to the corresponding pins of the CPU as the third group of four-channel pins, thus establishing an IIC signal channel based on group B1 signals. Group B1 signals are based on the IIC protocol, where the EC_TP_ON signal is the touchpad presence signal, used to prompt the EC that the touchpad is connected; the EC_INT_N signal is the interrupt signal, used to prompt the EC to disconnect the control of the touchpad. The IIC protocol is different from the PS2 protocol. Comparatively, the IIC protocol is more powerful and can control more. Therefore, when the touchpad uses the IIC protocol, through the I2CDT1 and I2CCK1 signals, the IIC can simultaneously control the left and right buttons (equivalent to the mouse buttons) and the sliding control of the touchpad.

[0031] Comparing the two groups of signals B1 and B2, it can be seen that under the PS2 protocol, there is no need for the in-position signal EC_TP_ON and the interrupt signal EC_INT_N. This is because the PS2 signal is directly connected to the EC, and the EC can directly detect it. For signals like IIC, according to the pre-designed devices involved in driving the IIC touchpad, it can be output by the EC or by the CPU / PCH. Therefore, the EC needs to pull out two additional signals to detect the in-position signal and the interrupt signal.

[0032] The 16th pin of the chip RS2233YTSS16 is electrically connected to the 3.3V standby power supply on the main board for power supply. The 1st pin of the chip RS2233YTSS16 serves as the selection pin, and the GPIO signal CPU_GPIO1 from the CPU is input. According to the level of the signal, it controls whether the A-group signal is connected to the B1-group signal or the B2-group signal.

[0033] It should be noted that, as an example Figure 2 and Figure 3 In, the signals on the A-group pins of the chip RS2233YTSS16 and the corresponding pins on the touchpad connector are marked with the touchpad signals under the PS2 protocol as an example, only to illustrate the pin alignment connection relationship between the two. It can be understood that when the touchpad connector is connected to an IIC touchpad, the signals on the aforementioned pins will change to the touchpad signals under the IIC protocol, which will not be elaborated here.

[0034] Referring to Table 1 below, in this preferred embodiment, the PS2 signal and the IIC signal are respectively connected to the B1 and B2 ports of the RS2233YTSS16 chip, and then the selection pin of the RS2233YTSS16 chip (the IN pin in the function table, Figure 2 the S pin in ) is connected to the GPIO of the CPU. When the circuit of the present invention is specifically applied to a computer system, PS2 and IIC touchpad adaptability can be achieved. For example, during the BIOS initialization stage of the computer system, the GPIO is first defaulted to a low level. At this time, A = B1, ensuring that the IIC channel is open. If the BIOS scans an IIC device, the GPIO is kept at a low level, and at this time the IIC touchpad can be used normally; if the BIOS does not scan an IIC device, the GPIO is pulled high, and at this time A = B2, and the PS2 signal channel is open, and at this time the PS2 touchpad can be used normally.

[0035] Table 1. Function Table of RS2233YTSS16 Chip

[0036]

[0037] Furthermore, as in Figure 3As shown in the upper part, in this preferred embodiment, pull-up resistors R269 and R270 are also added. If the wires of the touchpad are too long, the driving ability of the signal coming out of the RS2233YTSS16 chip can be increased.

[0038] In summary, the PS2 and IIC touchpad selection circuit on the motherboard of the portable computer of the present utility model realizes the simultaneous support of PS2 and IIC touchpads on the same motherboard design through a simple circuit design.

[0039] As described above, for those of ordinary skill in the art, various corresponding changes and deformations can be made according to the technical solution and technical concept of the present utility model, and all such changes and deformations should fall within the protection scope of the appended claims of the present utility model.

Claims

1. A PS2 and IIC touchpad selection circuit on a portable computer motherboard, characterized in that, Comprising: A four-channel SPDT switch, and a touchpad connector supporting connection with a PS2 touchpad and an IIC touchpad; the four-channel SPDT switch includes a first set of four-channel pins electrically connected to the touchpad connector, a second set of four-channel pins for communicating based on PS2 signals, a third set of four-channel pins for communicating based on IIC signals, and a selection pin; the four-channel SPDT switch selects to connect the second set of four-channel pins or the third set of four-channel pins to the first set of four-channel pins according to whether the level input to the selection pin is high or low.

2. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 1, wherein, The selection pin is electrically connected to the GPIO pin of the CPU to input a selection signal from the CPU.

3. The PS2 and IIC touchpad selection circuit on the portable computer motherboard as claimed in claim 1, wherein The second set of four-channel pins is electrically connected to the EC.

4. The PS2 and IIC touchpad selection circuit on the portable computer motherboard as claimed in claim 1, wherein The third set of four-channel pins is electrically connected to the EC.

5. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 1, characterized in that, Among the four pins included in the third set of four-channel pins, two pins are electrically connected to the EC, and the other two pins are electrically connected to the CPU or the PCH.

6. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 1, characterized in that, The four-channel SPDT switch is the chip RS2233YTSS16.

7. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 6, characterized in that, Pins 12, 9, 7, and 4 of the chip RS2233YTSS16 are electrically connected to the corresponding pins of the touchpad connector as the first set of four-channel pins.

8. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 6, wherein, Pins 13, 10, 6, and 3 of the chip RS2233YTSS16 are used as the second set of four-channel pins.

9. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 6, wherein, Pins 14, 11, 5, and 2 of the chip RS2233YTSS16 are used as the third set of four-channel pins.

10. The PS2 and IIC touchpad selection circuit on the portable computer motherboard according to claim 6, characterized in that, Pin 16 of the chip RS2233YTSS16 is electrically connected to the 3.3V standby power supply on the main board.

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