Abstract: A method and computer apparatus are presented for providing a secure data architecture for computer memory of a processor. The apparatus comprises a memory unit and a processing unit. Data are stored in the memory unit and manipulated by the processing unit, which is programmed to implement the data architecture. Tagged single data words are formed by concatenating a tag to each of the single data words. Each of the tags takes a value that corresponds to the data type of the single data word to which it is concatenated. A data multiword is creating by concatenating tagged single data words having the same data type. The data multiword is stored within a location in the computer memory, the location selected to ensure alignment of the data multiword in accordance with its length. An effective tag value is constructed for the data multiword by concatenating all of its single word tags.

Abstract: A compiler optimization method for optimizing a scheduled block of instructions inserts a conditional branch instruction in place of a merge instruction to select between alternative paths when a condition is resolved.

Abstract: A method, implemented by a compiler, for removing a store-load dependency from a critical path utilizes a compare address operation to determine at run time whether dependency actual exists. The operand to be stored is held in a temporary register and provided directly to the operations, using load operation result, in dependence on the value of the compare address operation result, so that the dependency is removed.

Abstract: Compiler optimization methods and systems for preventing delays associated with a speculative load operation on a data when the data is not in the data cache of a processor. A compiler optimizer analyzes various criteria to determine whether a cache miss savings transformation is useful. Depending on the results of the analysis, the load operation and/or the successor operations to the load operation are transferred into a predicated mode of operation to enhance overall system efficiency and execution speed.

Abstract: A method and apparatus for solving the output dependence problem in an explicit parallelism architecture microprocessor with consideration for implementation of the precise exception. In case of an output dependence hazard, the issue into bypass of a result of the earlier issued operation having an output hazard is cancelled. Latencies of short instructions are aligned by including additional stages on the way of writing the results into the register file in shorter executive units, which allows to save the issue order while writing the results into the register file. For long and unpredictable latencies of the instructions, writing of the result of the earlier issued operation having an output dependence hazard into the register file is cancelled after checking for no precise exception condition. All additional stages are connected to the bypass not to increase the result access time in case of this result use in the following operations.

Abstract: A method for optimizing a software pipelineable loop in a software code is provided. The loop comprises one or more pipelined stages and one or more loop operations. The method comprises evaluating an initiation interval time (IN) for a pipelined stage of the loop. A loop operation time latency (Tld) and a number of loop operations (Np) from the pipelined stages to peel based on IN and Tld is then determined. The loop operation is peeled Np times and copied before the loop in the software code. A vector of registers is allocated and the results of the peeled loop operations and a result of an original loop operation is assigned to the vector of registers. Memory addresses for the results of the peeled loop operations and original loop operation are also assigned.

Abstract: A high-speed sense amplifier includes a pair of cross-coupled inverters coupled to intermediate nodes and then to differential inputs nodes by a control circuit. The intermediate nodes are coupled together by a accelerator transistor that forms a current path when the sense amplifier is placed in a sensing state to provide parallel discharge paths for one or the other of output nodes. During precharge, the accelerator transistor operates to equalize the intermediate nodes to ready them for the next sense phase.

Abstract: A method for scheduling a plurality of operations of one or more types of operations including a plurality of computing resources is provided. The method includes building a list of partial lists for the one or more types of operations where the partial lists include one or more operations. A current partial list of a type of operation is determined. A computing resource for an operation in the current partial list is then allocated. The method then determines if additional computing resources for the type of operation are available for the current partial list. If so, the method reiterates back to determining a current partial list. If additional computing resources are not available, the method performs the steps of excluding the current partial list from the list and if the list includes any other partial lists, reiterating back to determining a current partial list.

Abstract: Computer method of compiling a multi-way decision statement for VLIW processing is described. The method comprises: (a) generating profile data for a multi-way decision statement, such a s a switch statement; identifying at least one most probable alternative of the multi-way decision and a set of constants associated with the identified alternative using the profile data; determining a probable subset of the identified constants based on the profile data; constructing a conditional statement for the identified alternative using the probable subset of constants; and moving out the identified at least one alternative from the multi-way decision statement.

Abstract: A power system for controlling power to low voltage CMOS circuits. The power system can be used in circuits having a low voltage supply and a high voltage supply, wherein the low voltage supply powers low voltage circuit components and the high voltage supply powers high voltage circuit components. The power system comprises a first switch coupled between the low voltage supply and the low voltage circuit components, a second switch coupled between the low voltage circuit components and a circuit ground, and a power control circuit coupled to the high voltage supply and the circuit ground and having a control output coupled to the first and second switches, wherein when the control output is in a first state the low voltage supply and the circuit ground are connected to the low voltage circuit components and when the control output is in a second state the low voltage supply and the circuit ground are disconnected from the low voltage circuit components.

Abstract: A data transfer arrangement. The data transfer arrangement includes two active pull up/active pull down bus drivers and a voltage precharge source. A differential bus is coupled to the bus drivers and to the voltage precharge source. A latching sense amplifier is coupled to the differential bus and serves as the bus receiver. The bus drivers operate in a precharge phase and a data transfer phase. The bus receiver operates in an analogous but opposite manner, i.e., when the bus drivers are in the precharge phase, the bus receiver is in the data transfer phase and when the bus drivers are in the data transfer phase, the bus receiver is in a precharge phase.

Abstract: A technique for constant bit folding, implemented by a compiler, logically processes only operand bits to generate bit sets useful for simplifying expressions. Bit sets indicating constant bits and constant bit values of the operands are generated and then logically processed to generate bit sets indicating constant bits and constant bit values of the results. Additionally, a bit set indicating operand bits that do not influence the result are generated.

Abstract: A method optimizes function evaluations performed by of a VLIW processor through enhanced parallelism by evaluating the function by table approximation using decomposition into a Taylor series.

Abstract: A clocked CMOS sense amplifier for high speed latching of low voltage complementary signals. The present invention includes a sense amplifier having a controlled cross-coupled transistor structure, a control circuit, a current source, a recovery transistor and protective transistors. A CORE circuit is provided which may be used to form different logic structures. Two large n-channel transistors in a discharging chain are used in combination with the small capacitances of the cross-coupled nodes to provide maximum speed and high output.

Abstract: A pipelined domino architecture includes pairs of pipeline stages each comprising a first active clocked stage and a number of subsequent self-reset logic gates. Each pipeline stage is clocked by one or the other of a clock signal. Each active clocked stage and self-reset logic gate of any particular pipeline state includes a reset circuit to reset the output of such stage or gate at the conclusion of an evaluation period that is initiated by a phase of the clock signal. Only the active clocked stage is clocked; the self-reset logic stages rely upon the reset of the output of the active clocked stage to generate the necessary reset signals that will reset their respective outputs.

Abstract: A system for increasing the speed and noise immunity of signals transmitted in low voltage CMOS applications. The system includes a transmission device for transmitting a signal in a CMOS circuit, wherein the CMOS circuit includes a high voltage power supply and a low voltage power supply and the signal is transmitted between first and second portions of the CMOS circuit that are coupled to the low voltage power supply.

Abstract: An apparatus for adjusting static thresholds of CMOS circuits. The apparatus includes a low reference circuit including at least one channel n-channel MOS device having a back gate and a high reference circuit including at least one p-channel MOS device having a back gate. A feedback loop is provided for providing a control voltage to the back gate of the n-channel NMOS device while a second feedback loop is provided for providing a second control voltage to the back gate of the p-channel MOS device. A control voltage is applied to the first feedback loop while a control voltage is applied to the second feedback loop. The output of the low reference circuit is coupled to the first feedback loop and the output of the high reference circuit is coupled to the second feedback loop.

Abstract: A method and system for use with VLIW processing architectures for avoiding redundant speculative computations in the compilation of the innermost loops. The method includes identifying a plurality of compiled flow paths, where each of the paths includes a plurality of conditions associated with the loop that permits transformation of the loop for more optimum execution. It is then determined whether the loop has an inductive variable and a conditional statement that depends on the inductive variable. It is also determined whether the loop set up values of the inductive variables to subsets, and at least one of which the conditional statement is a loop invariant. Finally, if conditions in the determination steps satisfy the conditions of one of the paths, the loop is transformed into two consecutive loops executable with a reduced set of values of the inductive variable.

Abstract: A fully static level translation circuit having a standby power close to zero. The level translation circuit for translating the voltage level of an input signal having a first voltage level to form an output signal having a second voltage level. The translation circuit comprises an input stage having logic to receive the input signal having the first voltage level and to create a first stage output signal, an output stage having logic to receive the first stage output signal and produce the output signal having the second voltage level, and a reset stage having logic to receive the first stage output signal and the output signal and to produce a reset stage output signal that is coupled to the output stage.

Abstract: The present invention decreases the delay associated with loading an array from memory by employing an asynchronous array preload unit. The asynchronous array preload unit provides continuous preliminary loading of data arrays located in a memory subsystem into a prefetch buffer. Array loading is performed asynchronously with respect to execution of the main program.