Transmission circuit, data transfer control device and electronic equipment

A technology for transmitting circuits and circuits, which is applied in transmission line coupling devices, digital transmission systems, electrical digital data processing, etc., can solve problems such as inability to transmit data normally, achieve the effect of improving the receiving probability and reducing the scale of the circuit

CN1702640AActive Publication Date: 2005-11-30SEIKO EPSON CORP
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2005-11-30

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Abstract

This invention provides a transmission circuit which can adequately perform a fast data transmission even to a receiving circuit of a host controller or a device controller with a low sensitivity. A transmission circuit transmitting a signal through first and second signal lines that form a differential pair and includes a first terminating resistor terminating the first signal line, a second terminating resistor terminating the second signal line and a terminating resistance control circuit generating a control signal for controlling terminating resistance values of the first terminating resistor and the second terminating resistor. A first resistor takes a first resistance value if a first control signal is active, a nth resistor takes a nth resistance value if a nth control signal is active, the first-nth resistors are coupled, one end of the coupled first-nth resistors is coupled to a reference potential and the other end is coupled to the first signal line or the second signal line. The terminating resistance control circuit generates the first-nth control signals based on terminating resistance configuration information.
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Description

technical field

[0001] The invention relates to a sending circuit, a data transmission control device and electronic equipment. Background technique

[0002] In data transmission control using differential signals, for example, the USB (Universal-Serial-Bus) standard is well known as an interface standard for connecting a personal computer and its peripheral devices. In recent years, with the sharp increase in the demand for high-speed data transmission, products that meet the high-speed (High Speed) newly defined in USB2. Speed ​​), full speed (Full Speed) higher speed data transmission. In order to realize normal data transfer, various studies have been made on a data transfer control device and the like corresponding to the high speed (High Speed) of the USB2.0 standard (see Patent Document 1).

[0003] For example, in the Low Speed ​​and Full Speed ​​determined according to the USB1.1 standard and the USB2.0 standard, even if the device controller sending data or the h...

Examples

Embodiment Construction

[0042] Hereinafter, one embodiment of the present invention will be described with reference to the drawings, and the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all the configurations described below are essential components of the present invention.

[0043] 1.USB2.0

[0044] According to USB2.0, in addition to Low Speed ​​and Full Speed ​​stipulated by USB1.1, High Speed, which can theoretically perform high-speed transmission of 480Mbps, is also newly stipulated. A plurality of peripheral devices corresponding to the USB standard (sometimes also called devices, hereinafter the same) have device controllers, and can be connected to a personal computer (sometimes called host, hereinafter the same) with a host controller, the host controller through the bus to manage the bus. In addition, a hub device (HUB device) may be connected between the peripheral device and the personal computer.

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