System for automatic identification of a computer data entry device interface type using a transistor to sense the voltage generated by the interface and output a matching voltage level
First Claim
1. A system, used in a computer pointing device generating movement data, for the automatic identification of an interface type of a pointing device interface, the system comprising:
- a sense line coupled between the interface and the pointing device, said sense line having a first voltage level generated by the interlace if the interface is a first interface type and a second voltage level, different from said first voltage level, generated by the interface if the interface is a second interface type;
a transistor having a first terminal coupled to said sense line, said transistor having a second terminal in a first output state if said sense line is at said first voltage level and in a second output state if said sense line is at said second voltage level; and
a processor coupled to said transistor second terminal and processing the movement data in a first manner if said second terminal is in said first output state and processing the movement data in a second manner if said second terminal is in said second output state.
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Accused Products
Abstract
A circuit using a single transistor to detect the interface type to Which a combination pointing device is connected. The pointing device may be connected to a PS/2 interface, which generates a voltage greater than or equal to 0 volts, or a serial interface which generates a negative voltage. The transistor is activated when connected to the serial interface, and is inactive when connected to the PS/2 interface. The output of the transistor is sensed by a microcontroller within the pointing device. The microcontroller generates data for transmission to the PS/2 interface if the transistor is not active, and generates data for transmission to the serial interface if the transistor is active. An I/O pin in the microcontroller is used to sense the interface type and can also be used as an output in which the microcontroller generates control signals for use by the pointing device. This multitasking operation reduces the required pin count of the microcontroller, thus reducing cost.
164 Citations
36 Claims
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1. A system, used in a computer pointing device generating movement data, for the automatic identification of an interface type of a pointing device interface, the system comprising:
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a sense line coupled between the interface and the pointing device, said sense line having a first voltage level generated by the interlace if the interface is a first interface type and a second voltage level, different from said first voltage level, generated by the interface if the interface is a second interface type; a transistor having a first terminal coupled to said sense line, said transistor having a second terminal in a first output state if said sense line is at said first voltage level and in a second output state if said sense line is at said second voltage level; and a processor coupled to said transistor second terminal and processing the movement data in a first manner if said second terminal is in said first output state and processing the movement data in a second manner if said second terminal is in said second output state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A computer data entry device capable of the automatic identification of an interface type, for use with a pointing device interface generating a first voltage level if the interface is a first interface type and a generating second voltage level different from the first voltage level if the interface is a second interface type, the computer data entry device comprising:
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a position sensing circuit generating positional data in response to user manipulation of the data entry device; and a transistor coupled to the interface to sense the voltage generated by the interface, said transistor having an output terminal to produce an output voltage having a first output level if the interface is generating the first voltage level and a second output level if the interface is generating the second voltage level; and a processor coupled to said transistor output terminal to sense said output voltage levels, said processor processing said positional data in a first manner if the interface is generating the first voltage level and processing said positional data in a second manner if the interface is generating the second voltage level. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method for use with a computer data entry device for the automatic identification of a data entry device interface type, the interface generating a first voltage level if the interface is a first interface type and a generating second voltage level different from the first voltage level if the interface is a second interface, the method comprising the steps of:
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generating positional data in response to user manipulation of the data entry device; sensing the voltage generated by the interface using a transistor coupled to the interface, and processing said positional data in a first manner if said sensed voltage on said transistor is the first voltage level and processing said positional data in a second manner if said sensed voltage on said transistor is the second voltage level. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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Specification