Silicon Integrated Systems Corporation

Tsan-Hui Chen

Jen-Pin Su

Wen-Hsiang Lin

Chun-Chieh Wu

Ming-Hsien Lee

Han-Ning Chen

Chang-Fu Lin

Jew-Yong Kuo

Ming-Shien Lee

Shao-Kuang Lee

An aligned clock forwarding scheme of an electronic system includes a first circuit path generating an aligned clock output signal to a subsystem and a second circuit path generating an aligned data signal to the subsystem. An external clock input serves as the source of the clock signal for the aligned clock forwarding scheme. A multiplication circuit receives the external clock input and sends multiplied clock signals to control the first and second circuit paths. The two circuit paths have the same physical characteristics so that both clock output and data signals experience the same environmental effect. There is no additional skew incurred between the clock and data signals during the data transfer between the two subsystems.

Aligned clock forwarding scheme

A mechanism for maintaining the first-in first-out order of commands in a multiple-input and multiple-output buffer structure includes a command number generator for generating and assigning a command number to each command entering the buffer structure, and a command number comparator for comparing the command number of the outgoing command at each buffer in the buffer structure to determine which command should exit. Both command number generator and command comparator have a cyclic counter that has a period greater than or equal to the total number of allowable buffer entries in the buffer structure. For maintaining order of posted and non-posted command queues, a pending posted write counter is used in the posted command queue to record the number of pending posted write command and each entry in the non-posted command queue is associated with a dependency counter.

Command order maintenance scheme for multi-in/multi-out FIFO in multi-threaded I/O links

The present invention discloses an apparatus and system for multi-stage event synchronization, whose main object is to eliminate the drawbacks of an expensive synchronization circuit used to balance the data transmissions between an origination agent and a destination agent operating at different frequencies or clock phases as in prior art. The apparatus of the present invention organizes the slower one with multi-stage chains, each of which comprises a simple synchronization circuit and an XOR gate, for receiving the number of events transmitted from the faster one. Therefore, the slower one will not miss the data from the faster one.

Apparatus and system for multi-stage event synchronization

This present invention discloses a circuit for generating a delay signal, which includes a first delay line for generating a first delay signal, a second delay line for generating a second delay signal, a delay unit for generating an internal delay signal, a first phase detector for generating a first control signal, a second phase detector for generating a second control signal. There's a delay line monitor for generating the first delay control signal and the second delay control signal, and a DTC delay unit for generating the delay signal.

Fast-locking dual rail digital delayed locked loop

In a memory controller system, a method for granting a system memory by a memory request arbitrator to a request among a plurality of pending memory access requests is provided. The plurality of the memory access requests includes Rfrsh_Hreq, Crt_Hreq, Group AB, Crt_Lreq and Rfrsh_Lreq and are respectively asserted by a host control circuitry and/or a graphical control circuitry which are implemented and integrated on a single monolithic semiconductor chip. The host control circuitry and the graphical control circuitry shares the system memory and the memory request arbitrator includes a refresh queue and the graphics control circuitry includes a CRT FIFO. The method prioritizes the plurality of the memory access requests in order of Rfrsh_Hreq>Crt_Hreq>Group AB>Crt_Lreq>Rfrsh_Lreq. The Rfsh_Hreq is memory refresh request signal of first type whenever the refresh queue being full, the Crt_Hreq is memory access signal of a first type for fueling the CRT FIFO with display data, the Group AB are memory access request signals of a second type output either from the graphical control circuitry or the host control circuitry, the Crt_Lreq is memory access signal of a third type for fueling the CRT FIFO with display data, the Rfrsh_Lreq is memory refresh request signal of second type whenever the refresh queue being non-empty.

Growing community of inventors

Hsinchu, Taiwan

Tsan-Hui Chen