Transmission circuit, data transfer control device and electronic equipment

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.

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...

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Problems solved by technology

[0005] For example, when the host controller for receiving data does not comply with the design items stipulated in the standard as mentioned above, even if the device controller for sending data is a product that strictly complies with the design items and transmits waveforms that meet the standards signal, and sometimes the data cannot be transmitted normally

[0006] In addition, similarly, the device controller for receiving data, as mentioned above, in the case of not complying with the design matters stipulated in the standard, even if the host controller that transmits data is a product that strictly complies with the design matters and sends a Waveform signal, sometimes can not transmit data normally

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