Abstract: A method of detection is described to be used in file system-based player devices to determine the type of compact disk that has been inserted into a player. The method automatically distinguishes between the DTS-CD format and standard audio CDs. The method allows the operating system or CPU software to take appropriate action to decode and playback the audio stream once the a decision between standard audio CD or DTS-CD is made.

Abstract: A method and apparatus for decoding digital quadrature phase shift keying data includes converting and intermediate frequency signal from an analog signal to a digital signal and digitally processing the digital signal to detect and decode the digital quadrature phase shift keying and extract encoded data.

Abstract: A method of detection is described to be used in file system-based player devices to determine the type of compact disk that has been inserted into a player. The method automatically distinguishes between the DTS-CD format and standard audio CDs. The method allows the operating system or CPU software to take appropriate action to decode and playback the audio stream once the a decision between standard audio CD or DTS-CD is made.

Abstract: A programming algorithm reduces from ? (2N2) to ? (N2) the number of multiply-and-accumulate (MAC) instructions required to perform a discrete-time convolution on a programmable digital signal processor. Through the use of a single repeat instruction along with a single repeat count register, the algorithm dynamically changes the number of times the multiply-accumulate instruction is repeated depending upon the current term being convolved. The avoids performing the multiply-accumulate when one term is zero. The nature of the discrete-time convolution calculation and the flexibility of a re-programmable single repeat count register offers permits this. Additional instructions are required for data pointer alignment. The trade-off between reduced multiply-accumulate operations and the overhead required to achieve it is examined.

Abstract: A method to supply audio effects to video games employs graphics information of sound source objects and sound interacting objects in a real time physical model to determine the audio effects. Each sound source and sound interacting object is associated with a computer generated object in the graphical environment. The physical model determines how the sound interacts with the environment at the current object locations and applies the audio effects. The game designer does not need to dub in audio effects artificially in an add-on manner.

Abstract: This invention describes the use of dynamic sound source and listener position (DSSLP) based audio rendering to achieve high quality audio effects using only a moderate amount of increased audio processing. Instead of modeling the audio system based on sound and listener position only, the properties that determine the final sound are determined by the change in listener relative position from the current state and last state. This storage of the previous state allows for the calculation of audio effects generated by change in relative position between all sound sources and listener positions.

Abstract: In an embedded symmetric multiprocessor (ESMP) system it is desirable to maintain equal central processing unit load balance. When an interrupt occurs, a single central processing receives the interrupt and then passes information to the central processing unit scheduling software. This software will in turn determine which central processing unit can best handle the interrupt. Because the scheduling software is able to determine which central processing unit handles the interrupt process, it can maintain central processing unit load balancing resulting in better system performance.

Abstract: A single chip, embedded symmetric multiprocessor (ESMP) having parallel multiprocessing architecture composed of identical processors includes a single program memory. Program access arbitration logic supplies an instruction to a single requesting central processing unit at a time. Shared memory access arbitration logic can supply data from separate simultaneously accessible memory banks or arbitrate among central processing units for access. The system may simulate an atomic read/modify/write instruction by prohibiting access to the one address by another central processing unit for a predetermined number of memory cycles following a read access to one of a predetermined set of addresses in said shared memory.

Abstract: This invention is a method of complex cache memory analysis and synthesis. This invention proceeds in the normal fashion of writing a program and simulating it, but makes use of a closed loop design approach to completing the analysis-synthesis process. A program behavior analysis tool PBAT is integrated as part of an otherwise conventional program development tool. The PBAT offers a single environment where code development, simulator trace capture, and cache analysis take place. The cache analysis tool of PBAT is designed to match the current cache design of the processor and to identify any weakness in the current design or special features that need to be added. Code adjustments are passed back to the assembler and linker and in successive simulations using the integrated PBAT tool resulting in code that better fits a specific cache design.

Abstract: An embedded symmetrical multiprocessor system includes arbitration logic that determines which central processing unit has access to shared memory. Upon grant of access, the memory address is stored in a memory address register. An address compare circuit compares the access address of any other central processing unit with this stored address. Upon a match, the arbitration logic stalls the second accessing central processing unit until expiration of a programmable number of wait states following the first access. These wait states give the first central processing unit enough time to determine the state of a lock variable and take control of an operation protected by the lock variable. The application boot code can determine how long the read-check-write operation requires and program that value into the wait-state generator.

Abstract: A test signal multiplexer receives supplies external test signals to a selected debug master central processing unit in a symmetrical multiprocessor system and debug slave signals to debug slave central processing units. An executive master test access port controller responds to the external test signals and controls the test signal multiplexer. A control register loadable via the executive master test access port stores the debug slave signals. A test data output multiplexer connects the test data output line of the selected debug master central processor unit to an external test data output line. The external test signals includes a debug state signal supplied to each central processing unit. This selects either a normal mode or a debug mode at each central processor unit.

Abstract: In multiprocessor systems the task of holding power dissipation to its lowest possible level is challenging. This invention permits reduced power dissipation by optionally independently clocking selected central processing units at lower frequencies if they are not fully loaded. The variable clocking system enables synchronization between central processing units operating a differing frequencies and shared memory and peripherals. This allows for significant power reduction in the frequently occurring scenario where all processors are not driven to their limits by prevailing system requirements.

Abstract: The immediate grant bus arbiter of this invention is a part in the implementation of a multiple transaction bus system. A bus bridge provides a means to connect two separate busses together and secure data integrity. The bus bridge is defined with clear master-slave protocol. The bus bridge normally involves the use of two arbiters. The arbiter on the primary bus needs to operate differently from the arbiter on the secondary bus due to real system time constraints. This invention defines a bus arbiter that allows for a dominant bus master to receive an immediate grant of control on the bus. This immediate grant bus arbiter never relinquishes the bus if another lower priority master makes a bus request. This makes predictable real time data transfer possible.

Abstract: A bus bridge is defined to provide an interface between two AHB buses. These busses normally have separate requirements but both must provide high performance. The first is for transfer of data from CPU to memory and peripherals. The second is to support the transfer of a large amount of data by a single peripheral to local memory or other local peripherals. The AHB-to-HTB bus bridge provides a means for the interfacing these two separate AHB buses allowing communication between them and securing data integrity. The bus bridge of this invention is defined to be an AHB memory bus slave but a high performance data transfer bus master.

Abstract: A micro-controller direct memory access (DMA) unit includes hardware support for single read of the source address at a source word size and but writes to the target address at an independent target word size. This permits, for example, a single read of the source address at a larger word size and multiple sub-word sized writes to the target address. This is enabled by independent control register storage of a source word size, a source increment size, a target word size and a target increment size. A byte shifter/register that will shifts a full byte at a time to the next lower byte position allowing transfer of a large word to a destination having a small word size.

Abstract: This invention comprises a multiple transaction advanced high performance bus AHB system using two separate fully autonomous AHB buses, each having its own bus arbitration system with decoding to allow for simultaneous activity on the two AHB buses. The two buses are separated by and synchronized with an AHB-to-HTB bus bridge. The first bus, the Memory Bus AHB, contains the CPU and DMA as bus masters and the external memory controller and internal memory as slaves. The second bus, the Data Transfer Bus HTB, contains the high performance peripheral and any local RAM required.

Abstract: The time-out counter of this invention provides a capability in a bus bridge for a first bus master to generate a time-out interrupt on reads from a second bus device if it is not given control of the second bus within a certain time period when the time of arbitration on the second bus is excessive. The time-out counter is programmable up to 16-bits and allowing the software selection of the time-out length. This time-out feature is useful if the manner of arbitration used would otherwise allow the second bus master to have absolute control of the first bus. Address and data FIFO buffers are used for writes to a second bus device.

Abstract: A configurable memory controller for an AMBA system is described. This configurable memory controller selects one of two possible modes of operation. The technique of configuring the memory controller provides fundamental memory control in the AMBA system while also allowing for a switching mechanism to select between the two modes, each of which entails its own set of special signal definitions. The configurable memory controller may be connected either on the AHB bus or directly connected to the ARM central processing unit core with a mechanism to switch between the two modes of operation.

Abstract: An embedded symmetrical multiprocessor system includes arbitration logic that determines which central processing unit has access to shared memory. Upon grant of access, the memory address is stored in a memory address register. An address compare circuit compares the access address of any other central processing unit with this stored address. Upon a match, the arbitration logic stalls the second accessing central processing unit until expiration of a programmable number of wait states following the first access. These wait states give the first central processing unit enough time to determine the state of a lock variable and take control of an operation protected by the lock variable. The application boot code can determine how long the read-check-write operation requires and program that value into the wait-state generator.

Abstract: A programming algorithm reduces from &thgr; (2N2) to &thgr; (N2) the number of multiply-and-accumulate (MAC) instructions required to perform a discrete-time convolution on a programmable digital signal processor. Through the use of a single repeat instruction along with a single repeat count register, the algorithm dynamically changes the number of times the multiply-accumulate instruction is repeated depending upon the current term being convolved. The avoids performing the multiply-accumulate when one term is zero. The nature of the discrete-time convolution calculation and the flexibility of a re-programmable single repeat count register offers permits this. Additional instructions are required for data pointer alignment. The trade-off between reduced multiply-accumulate operations and the overhead required to achieve it is examined.