Patent ID: 9360949
Filing Date: 2016-06-07
CPC Classification: G06F,G09G

Claim Text:
1. A human interface device, comprising: a first press key and a second press key; a control chip comprising a multiplexing pin and a voltage detection circuit, wherein an external circuitry coupled to the multiplexing pin via a node, the external circuitry comprising a first multiplexer having an output coupled to the node and a second multiplexer having an output coupled to the node, wherein when the first press key and the second press key are not pressed, the node is coupled to the ground voltage via the first voltage drop and coupled to the voltage source via the third voltage drop to form a first voltage value on the multiplexing pin, when the first press key is pressed and the second press key is not pressed, the node is coupled to the ground voltage via the second voltage drop and coupled to the voltage source via the third voltage drop to form a second voltage value on the multiplexing pin, when the first press key is not pressed and the second press key is pressed, the node is coupled to the ground voltage via the first voltage drop and coupled to the voltage source via the fourth voltage drop to form a third voltage value on the multiplexing pin, when the first press key and the second press key are pressed, the node is coupled to the ground voltage via the second voltage drop and coupled to the voltage source via the fourth voltage drop to form a fourth voltage value on the multiplexing pin, the control chip is configured to identify that the first press key and the second press key are not pressed when the voltage detection circuit detects the first voltage value on the multiplexing pin, the control chip is configured to identify that the first press key is pressed and the second press key is not pressed when the voltage detection circuit detects the second voltage value on the multiplexing pin, the control chip is configured to identify that the first press key is not pressed and the second press key is pressed when the voltage detection circuit detects the third voltage value on the multiplexing pin, and the control chip is configured to identify that the first press key and the second press key are pressed when the voltage detection circuit detects the fourth voltage value on the multiplexing pin.