Via Technologies, Inc.

Chi-Che Tsai

Chau-Chad Tsai

Jiin Lai

Sheng-Chang Peng

Chen-Ping Yang

Chun-Yuan Su

Chih-Kuo Kao

Wen-Hao Chuang

Hsuan-Yi Wang

Chih-kuo Kao

The present invention provides a method of hot switching data transfer rate on the bus to hot switch the data transfer rate of the bus between the control chips without the process of RESET. When the bus between the control chips demands a large amount of data transfer, the bus is hot switched to a higher data transfer rate to fulfill the data transfer requirement. Contrarily, when the bus between the control chips demands less amount of data transfer, the bus is hot switched to a lower data transfer rate to save power consumption.

Method of hot switching data transfer rate on bus

An expansion adapter is used to communicate both PCI and AGP devices to the north bridge chip of a computer. The expansion adapter includes a first AGP bus control module communicable with the north bridge chip via a first AGP bus, and a second AGP bus control module in communication with the first AGP bus control module, communicable with an AGP device via a second AGP bus. The identifying codes of the first and second AGP bus control modules are set to show no AGP device function in order to allow the AGP device to communicate with the north bridge chip via the expansion adapter. The expansion adapter further includes a PCI bus control module in communication with the PCI device and the first AGP bus control module for controlling data transmission between the first AGP bus control module and the PCI device.

Expansion adapter supporting both PCI and AGP device functions

A data transmission sequencing method is disclosed. A data read operation from a primary bus to a secondary bus can be executed without having to wait for the complete transfer of write data stored in posted write buffer transferring to the primary bus, as long as the secondary bus is not in use. In the mean time of the primary bus issues a read operation to the secondary bus, the secondary bus can issues write operation to the bridging device when the secondary bus is not in use. Similarly, there is no need to wait for the completion of read operation. With this type of data transmission sequencing mechanism, idle sessions in a conventional transmission sequencing method are eliminated leading to a higher data transmission rate.

Data transmission sequencing method associated with briding device and application system

A bus data interface, structure and method for transmitting the data of a PCI bus is disclosed. The bus data interface comprises a high-bit transmitting buffer, a low-bit transmitting buffer, a multiplexer, a strobe generator, and a data distributor. The strobe generator utilizes the bus request signal and bus grant signal to transmit a data strobe signal in response to the PCI clock. According to the rising edge and falling edge of the data strobe signal, the data distributor retrieves data according to the data strobe signal. Further, the invention is compatible with the original PCI bus and allows the PCI bus to transmit data with a dual speed.

Interface, structure and method for transmitting data of PCI bus which uses bus request signal for judging whether a device supporting dual transmission mode

A bus for supporting plural signal line configurations and the method to switch it, used to operate in a bus between the control chips to maintain its operation flexibility. When the data transfer load in between the control chips is suitable for the bi-direction transfer, the signal line configuration of the bi-direction transfer is selected. When the direction of the bi-direction transfer switches frequently, the other signal line configuration is selected. That is, the bus signal lines are divided into two parts, each part is in charge of the data transfer in each uni-direction to avoid the turn around cycle that impacts the transfer performance.

Bus for supporting plural signal line configurations and switch method thereof

A peripheral device interface control chip having a cache system therein and a method of synchronization data transmission between the cache system and an external device in a computer system. The cache system and data synchronization method can be applied to the peripheral device interface control chip having a data buffer and a peripheral device interface controller. The data buffer is located inside the control chip for holding data stream read from a memory unit so that data required by the peripheral device is provided. When the data stream is still valid, the data stream is retained. The peripheral device interface controller is installed inside the control chip. The peripheral device interface controller detects if the data stream inside the data buffer includes the data required by the peripheral device and whether the data stream is still valid or not. The peripheral device interface controller also controls the placement of the data stream retrieved from the memory into the data buffer and state transition of the data buffer.

Peripheral device interface chip cache and data synchronization method

A bus arbitration method within a control chipset, The control chipset further comprises a first control chip and a second control chip, data are transferred between the first and the second control chips through a bus, the bus comprises a bidirectional bus The first control chip usually control the authority to use the bus, however the second control chip has higher priority to use the bus. Accompany with a bus specification without waiting cycle, to arbitrate the authority to use the bus can be done fast and without errors. Therefore, no GNT signal line is required and the arbitration time reduces.

Arbitration of control chipsets in bus transaction

A PCI data accessing system with a read request pipeline and an application method thereof are provided. The PCI data accessing system has a PCI master device, a memory module, and a PCI control device. The PCI master device issues a first read request, and the PCI control device converts the first read request to a second read request divided into a first part and a second part. Each part of the second request requests one line data, i.e. 64 bits data. The memory module stores data requested by the PCI master device. Moreover, there is no latency time between data for the first part and the second part returned from the memory module.

Data accessing system with an access request pipeline and access method thereof

A data transaction method between control chips. Data buffers of the control chips of the control chipset have fixed size and amount. In addition, read/write acknowledge commands are asserted in sequence according to read/write commands, by which the control chips can detect the status of the buffers within another control chips. When a control chip asserts a command, the corresponding data must be ready in advance. Therefore, the signal line for providing the waiting status, data transaction cycle and stop/retry protocol can be omitted. Accordingly, commands or data can be continuously transmitted without waiting, stop or retry, the performance is improved.

Control chipset, and data transaction method and signal transmission devices therefor

A method of adjusting an access sequencing scheme for a number of PCI (Peripheral Component Interconnect) compliant units coupled to a PCI bus system on a computer system. These PCI-compliant units are associated respectively with a set of request signals that allow these PCI-compliant units to request the use of the PCI bus system for data transfer. The access sequencing scheme includes a first-layer access sequence loop and a second-layer access sequence loop, with the first-layer access sequence loop having a higher priority over the second-layer access sequence loop The request signals are assigned to either the first-layer access sequence loop or the second-layer access sequence loop in a predetermined manner. The user can change the assignment of a certian request signal from one loop to the other through PC's BIOS (Basic Input/Output System), so as to allow the associated PCI-compliant unit to have a higher priority level to the use of the PCI bus system.

Method of adjusting an access sequencing scheme for a number of PCI- compliant units coupled to a PCI bus system

A two-way cache system for interfacing with a peripheral device and a method of operating a two-way cache system for carrying out data transmission between a peripheral device and a memory unit. The cache system has a two-way first-in first-out buffer region and a two-way cache controller. The two-way first-in first-out buffer region further has a first cache data region and a second cache data region. The first cache data region and the second cache data region are capable of holding a batch of first cache data and a batch of second cache data. The two-way cache controller receives a read request from the peripheral device. According to the read request, the requested data and data that ensues or comes after the requested data are retained by the two-way first-in first-out buffer (FIFO) region. If the peripheral device continues to request more data by maintaining a FRAME signal line in an enabled state, the first cache data region and the second cache data region are alternately used to read in subsequent data. A check may be made to see if requested data stored inside the two-way cache buffer region is coherent or consistent with data stored inside the memory unit.

Two-way cache system and method for interfacing a memory unit with a peripheral device using first and second cache data regions

Method and apparatus for arbitrating access to a pci bus by a plurality of functions in a multi-function master. The arbitrating method is performed among the multiple functions of a multi-function master. The arbiter includes a rotating inquiry scheduler (RIS) and a heuristic inquiry initiator (HII). The RIS receives the local inquiry signal from the functional circuit and stores it. According to the local inquiry signal, a bus inquiry signal is generated and sent to the HII, and is sent to the PCI bus to request a use of the PCI bus. If the PCI bus responds a delay transaction termination, the HII can repeatedly send the bus inquiry signal to the PCI bus until the PCI bus grants the privilege to use the PCI bus. The HII then informs the RIS, which arranges the functional circuit to transmit data through the PCI bus.

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Kaohsiung Hsien, Taiwan

Chi-Che Tsai