Method of and device for detecting cable connection using an oscillation circuit and a counter

• US 7,334,151 B2
• Filed: 06/07/2006
• Issued: 02/19/2008
• Est. Priority Date: 04/19/2001
• Status: Expired due to Term

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Mitsubishi Electric System (Mitsubishi Electric Corporation), Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Kubo, Kenji, Maemura, Hiroyuki, Tanaka, Wataru
• Primary Examiner(s): Trujillo, James K
• Application Number:
  US11/447,898
• Publication Number:
  US 20060248365A1
• Time in Patent Office: 622 Days
• Field of Search: 713/500, 713/501, 710/300, 710/301, 710/302
• US Class Current: 713/501
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 13/4072 Drivers or receivers G06F13/4086 takes precedence; for multistate logic circuits H03K19/0002
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The detector includes the plug for connecting the personal computer through a cable, battery power supply which provides a constant power supply, and the MCU which receives a specific potential from the personal computer when the later is connected.

Claims

1. A detector for detecting a wire connection with a personal computer, the detector comprising:

a plug for connecting the detector to the personal computer through a cable;

a battery power supply which outputs a predetermined constant electrical potential;

an oscillator which outputs an oscillation signal; and

a Micro Control Unit which receives a specific electrical potential from the personal computer through the plug and cable, receives the constant electrical potential from the battery power supply, and receives the oscillation signal from the oscillator, wherein the Micro Control Unit comprises;

a CPU and peripheral circuit which receives the specific electrical potential from the personal computer and the constant electrical potential from the battery power supply;

an oscillation circuit which detects a voltage level of the specific electrical potential from the personal computer, receives the oscillation signal from the oscillator, and outputs an oscillation output based on the detected voltage level and the oscillation signal; and

a counter which counts the oscillation output from the oscillation circuit and outputs a detection signal to the CPU and peripheral circuit.

2. The detector according to claim 1, wherein the Micro Control Unit comprises:

a PLL circuit which receives the oscillation output from the oscillation circuit and outputs a clock to the USB function circuit.

3. A method of detecting a wire connection with a personal computer using a detector, the detector including,

a plug for connecting the detector to the personal computer through a cable;

a battery power supply which outputs a predetermined constant electrical potential;

an oscillator which outputs an oscillation signal; and

a Micro Control Unit which receives a specific electrical potential from the personal computer through the plug and cable, receives the constant electrical potential from the battery power supply, and receives the oscillation signal from the oscillator, the Micro Control Unit including,

a CPU and peripheral circuit which receives the specific electrical potential from the personal computer and the constant electrical potential from the battery power supply;

an oscillation circuit which detects a voltage level of the specific electrical potential from the personal computer, receives the oscillation signal from the oscillator, and outputs an oscillation output based on the detected voltage level and the oscillation signal; and

a counter which counts the oscillation output from the oscillation circuit and outputs a detection signal to the CPU and peripheral circuit,

the method comprising the step of detecting, by the CPU and peripheral circuit, connection with the personal computer based on counting in the counter of the oscillation output from the oscillation circuit when the personal computer is connected to the detector.