Prolific Technology Inc.

Industrial Technology Research Institute

Wen-Hwa Chou

Yun-Kuo Lee

Kuo-Jen Kuo

Wen-Jen Wu

Yu-Kuo Chen

Hsin Hsia Wei

Yueh-Yao Nain

Arthur Wu

Chin-Yao Chang

Chi-Fang Ma

A rational number frequency multiplier circuit and a method for generating rational number multiple frequency are disclosed. The circuit receives a plurality of input signals having the same frequency and different phase, and outputs at least one multiple frequency signal. The rational number frequency multiplier circuit includes a frequency divider module, for receiving and dividing the input signals to output frequency-divided signals having the same frequency and different phase; a first phase synthesis module and a second phase synthesis module for receiving and synthesizing the frequency-divided and input signals respectively into a plurality of first pulse period signals and second pulse period signals; and an adder for receiving and combining the first pulse period signals and the second pulse period signals into the multiple frequency signal according to the desired multiplication of the frequency.

Rational number frequency multiplier circuit and method for generated rational number frequency

A universal serial bus (USB) with a power-saving mode and an operating method thereof are provided. When the USB peripheral is coupled to the USB host, the USB host core logic of the USB host transmits an inquiry request via a USB transceiver to inquire whether or not the USB peripheral supports the power-saving mode. The core logic of the USB peripheral responds via the USB transceiver that the power-saving mode is supported. Then the USB peripheral is off-line and then is shifted to be on-line for operating the power-saving mode. The USB host is also switched to the power-saving mode. Under the power-saving mode, the data are respectively transceived by the serial transceivers. The clock frequency of the serial transceiver can be adjusted according to the request of data transmission.

Universal serial bus and method for transmitting serial clock and serial data signals during power-saving mode

A plug and play device and an access control method, in which the plug and play device includes an access control device and a main function device. When the plug and play device is connected to a host, the access control device is first connected to the host to execute an authorization procedure. The user is not authorized if the authentication procedure rejects the user. In this case, the plug and play device denies the host control. Conversely, the user is authorized if the authentication procedure approves the user. In this case, the plug and play device connects the main function device to the host and accepts control by the host. After the host loads a proper driver, it may control the plug and play device.

Plug and play device and access control method therefor

A method of installing a driver for a plug and play device is provided, wherein the plug and play device includes a main function device and a storage device meeting a standard specification. The storage device stores a driver required by the main function device. The main function device and storage device may be connected to the host in two different ways after the plug and play device is installed to the host. The first way is to connect the two devices to the host simultaneously. The host loads a built-in standard driver for the storage device from the host to access the storage device, and then loads the driver required by the main function device from the storage device to gain freely access to the main function device. The second way is to connect the storage device to the host, and to cause the host to copy the main function device driver from the storage device to the host's storage device (e.g., a disk drive). Next, the main function device is connected to the host. At this time, the host can directly load the copied driver for the main function device and retrieve the device accordingly.

Method of installing a plug and play device driver

A Universal Serial Bus (USB) compound device and the method for implementation thereof are disclosed. The USB compound device does not include an embedded hub but simulates a hub by a circuit or firmware. Therefore, a set of independent function devices are able to connect to a USB bus via the same set of USB logic, and the production cost can be reduced without affecting the function of the device and the facility of expansion and plug-and-play function.

USB compound device operates a plurality of devices by using the same USB logic circuit and the method for implementation thereof

&ldquo;A portable MP3 player has two operation modes. In a first mode, the portable MP3 player operates independently. A controller in the MP3 player reads first MP3 files from internal memory and a MP3 decoder is utilized for decoding the MP3 files. In addition, the audio data are output to an earphone or a speaker. In a second mode, a ducking station is provided for placing the portable MP3 player, which has an extended memory device, e.g. CD-ROM, for storing second MP3 files. The controller of the portable MP3 player accesses the second MP3 files via interfaces that are connected when the portable MP3 player is placed on the ducking station. The MP3 decoder of the portable player is also utilized to decode the second MP3 files and the corresponding audio data are output through the ducking station.&rdquo;

Dual-mode MP3 player

A computer system cache memory has a caching tag which stores a subset of the L2 cache memory tag store. The caching tag is smaller, faster memory device than the L2 cache memory. The cache memory latency is reduced because the tag access time and tag comparison time are improved due to the caching tag. The caching tag may be manufactured to be located on the same chip as the cache controller, which allows faster data access than if the caching tag is located on a separate chip.

Growing community of inventors

Taipei, Taiwan

Wen-Hwa Chou