Vlsi Technology, Inc.

Gregg D Lahti

Gary D Hicok

Scott E Harrow

Franklyn H Story

Charles R Rimpo

The present invention relates to a system and a method for reducing access times for retrieving audio samples. The system uses a wave table cache. The wave table cache allows devices such as a Digital Signal Processor (DSP) to retrieve audio samples in a linear fashion from the wave table cache at a rate much faster than individually fetching the required portions of the audio sample from the main memory of the system. The DSP may then use the audio samples to generate signals to create sounds based on the audio samples.

System for reducing access times for retrieving audio samples and method

A method for storing and transferring wave table audio samples from system memory to a cache unit. The method creates a linked-list of pages in system memory for storing the audio sample. The linked-list is actually a pointer list indicating the locations in system memory where the audio samples are stored. A Digital Signal Processor (DSP) is able to translate the starting address of the pointer list to retrieve a requested audio sample from the system memory. The requested audio sample is then transferred to the cache unit where the DSP is able to retrieve audio samples in a linear fashion at a rate much faster than individually fetching the required portions of the audio sample from the main memory of the system.

Method for storing, transferring decompressing and reconstructing wave

Method for storing and transferring wave table audio samples using a DSP

A multi-mode infrared interface allows for the selection of an encoding mode from a plurality of modes for infrared light transmission. When there is a transmission, an outgoing serial data stream is produced. The infrared interface transmits the serial data stream by infrared light using the selected mode. For example, a first mode is serial data stream transmission where an IR light pulse is transmitted for each bit of data having a first value. A second mode is modulated serial data stream transmission where a modulated IR light pulse is transmitted for each bit of data having a first value. A third mode is REDEYE transmission using the HP Redeye 'REDEYE' format. A fourth mode uses a format defined by a user in software.

Multi-mode infrared input/output interface

A multi-purpose keyboard controller includes a matrix keyboard control circuit, a serial keyboard control circuit, a PC/AT port control circuit, and an external interface for RTC control. These control circuits are coupled in parallel with the interface logic of the computer system and use the built-in SMI interrupt mechanism of the computer system for reading and writing the keyboard or capturing keypress events. Software BIOS setup is employed to select one of the keyboard control circuits for utilization with the particular personal computer with which the system is employed. The interrupt scheme used by the keyboard interface uses SMI interrupts to the processor and SMI based software routines to read and write the values to and from the keyboard, thereby eliminating the need for dedicating a special hardware interrupt level; so that the system remains compatible with the DOS PC/AT Port 60/64h software interface.

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Chandler, AZ, United States of America

Gregg D Lahti