Abstract:
A system for displaying alphanumeric and graphic information on a raster scanned display device, for example, in a teletext system, includes a memory which is updated to change the display. Dynamic changes in the displayed image are provided by assigning a base address to each of one or more zones in the memory and altering the base addresses as required under local or remote control. Alphanumeric and graphic data may be combined on a single displayed page by means of identification data associated with each row or line of data to be displayed. The required capacity of the memory associated with the display device is substantially reduced by assigning a control code to data which is to be repetitively displayed, for example, spaces at the end of a line or fields of uniform color. Selected elements are thus displayed a predetermined number of times without the need for a corresponding number of memory locations. Incoming data may be sotred in a buffer memory at a greater rate than can be processed by the present system by means of a control circuit which inhibits the inputting of data for a period of time when there is a risk of overwriting or erasure of previously stored data.
Abstract:
A system for visualization on a video screen (6) in a graphical mode in which the visual information to be displayed is defined on the screen by a point by point sweeping, from page memory containing, at a given time, all of the video information to be displayed, and a video display processor (4), connected to a random access memory containing said page memory and to a display control unit (37) adapted to convert the information relative to the image composed from the contents of the memory (5) to screen (6) control signals, characterized in that central processing unit (1) is connected to the video display processor (4) by means of a single bus (12) over which are transmitted, on a time shared basis, the address fields and the data fields (15) and in that it includes in addition a control and interpretation circuit (27) capable, in response to an assignment signal generated by said central processing unit, to interpret the address field as an address field per se or as a control field for the video display processor.
Abstract:
System for direct access to a memory associated with a microprocessor data processing device comprising a direct access interface for introducing or extracting data in the memory during interruptions of the connection between the processing device and the memory, and a buffer interface operable during a portion of the access time of the processing device to the memory, to supply data addresses contained in the memory originating from the processing device and to enable circulation of corresponding data between the processing device and the memory, and during the remainder of the access time of the processing device, to the end of the access time, to store data transferred from the memory and to prevent transmission of data to the memory. A logic circuit controls inhibition of the buffer interface or of the direct access interface and, during the periods of inhibition of the buffer interface, permits the circulation of data and of addresses between the direct access interface and the memory.
Abstract:
A processor executes an instruction that causes a comparison to be performed between contents of a first register and contents of a second register and between the contents of the first register and a predetermined value. The instruction is particularly useful for determining whether an attempted access (either a load or write) to an array improperly targets a location outside the boundary of the array. In some embodiments, a system (e.g., a communication device such as cellular telephone) includes a processor capable of executing the instruction as described above.
Abstract:
Systems, methods, and storage media for accessing indirect memory in Java applications are provided. In some embodiments, a storage medium is provided that comprises Java application software that performs one or more operations on an indirect memory of a device. The software comprises instructions that create an instance of a Java class representing the indirect memory, and instructions that access a memory element of the indirect memory using an element unique identifier (“euid”) of the memory element. Other embodiments provide a method for accessing memory elements of a device that comprises creating an instance of a Java class representing the memory elements, and accessing a memory element of the memory elements using an element unique identifier (“euid”) of the memory element, wherein the memory elements are not mapped into the data memory space of the processor.
Abstract:
A processor may execute a test and skip instruction that includes or otherwise specifies at least two operands that are used in a comparison operation. Based on the results of the comparison, the instruction that follows the test and skip instruction is “skipped.” The test and skip instruction may specify that the operands used in the comparison include (1) the contents of two registers, (2) the contents of one register and the contents of a memory location, or (3) the contents of one register and a stack value. In the second mode (an operand being from memory), a register is specified in the test and skip instruction that contains a value from which a pointer may be calculated. The calculated pointer preferably points to the memory location. If a stack value is used in the execution of the test and skip instruction, the instruction may include a reference to a register that points to the top of the stack. Further, the stack pointer may be adjusted automatically if the stack is used to provide an operand for the instruction. Embodiments may include apparatus and methods.
Abstract:
A processor comprising a decode logic coupled to a first storage unit and comprising a data structure. The processor also comprises a second storage unit coupled to the decode logic. The decode logic obtains a single instruction from the first storage unit and, if indicated by a first bit in the data structure, processes a group of instructions in lieu of the single instruction, where the single instruction requires an operand. If indicated by a second bit in the data structure, the decode logic obtains the operand from the first storage unit, modifies the operand, and stores the operand to the second storage unit for use by the group of instructions.
Abstract:
A processor (e.g., a co-processor) capable of executing instructions sequentially, comprises at least two functional hardware resources. When two instructions that are consecutive in program order and are executed on two separate functional hardware resources, the execution of the two instructions may be parallelized if the two instructions are within a hardware loop. The processor thus, may implement a multiply and accumulate process in an efficient manner by performing the multiply instructions concurrently with the add instructions (which require fewer cycles to complete than the multiply instructions).
Abstract:
A digital system and method of operation is which the digital system has a processor with a virtual machine environment for interpretively executing instructions. First, a sequence of instructions is received (404) for execution by the virtual machine. The sequence of instructions is examined (408–414) to determine if a certain type of iterative sequence is present. If the certain type of iterative sequence is present, the iterative sequence is replaced (412) with a proprietary code sequence. After the modifications are complete, the modified sequence is executed in a manner that a portion of the sequence of instructions is executed in an interpretive manner (418); and the proprietary code sequences are executed directly by acceleration circuitry (420).
Abstract:
A digital system and method of operation is provided in which several processors (740(0)–740(n)) are connected to a shared resource (750). Each processor has an access priority register (1410) that is loaded with an access priority value by software executing on the processor. A memory management unit (MMU) (700) is connected to receive a request address (742) from each respective processor. The MMU has a set of entries that correspond to pages of address space. Each entry provides a set of attributes for the associated page of address space, including an address space priority value 309a. For each request, the MMU accesses an entry corresponding to the request address and provides an address space priority value associated with that requested address space page. Arbitration circuitry (1430) is connected to receive a request signal from each processor along with the access priority value from each access priority register and the address space priority value from each MMU. The arbitration circuitry is operable to schedule access to the shared resource according to higher of the pair of priority values provided by each processor.