Abstract: A circuit for converting a system supply voltage having one of two levels to a voltage for use by an integrated analog circuit connected to the system upon power-up. The circuit uses a diode-connected transistor to generate a reference voltage necessary for a regulator to regulate the supply voltage when the supply voltage is first powered up. The regulated supply voltage is doubled to a voltage level sufficient to activate the integrated analog circuit's bandgap voltage. The activated bandgap voltage is thus switched on to supply a more precise reference voltage to the regulator so that the diode-connected transistor may be de-activated to conserve power. The circuit also provides a bypass path for connecting the supply voltage directly to the integrated analog circuit when the supply voltage is the same level as the necessary voltage for the integrated analog circuit.

Abstract: A novel supply discriminator circuit is disclosed for detecting the level of a supply voltage during power-up of a system for configuring an integrated analog circuit such as a PCMCIA card. The circuit compares a reference voltage with a divided down supply voltage and latches the result a predetermined delay later. The delay thus provides timing for the supply voltage to stabilize after power-up to assure accurate detection, as well as noise immunity from other devices.

Abstract: The LOW POWER CRYSTAL OSCILLATOR shown here reduces power consumption of a Pierce oscillator which has an inverter preferably made of an NFET N0 and a PFET P0 in series. A load, preferably an NFET N1 with its gate wired to its source, is placed in parallel with a switch, preferably a PFET P1, between P0 and Vcc. A clamp, preferably a PFET P2 with its gate wired to its source, is placed in parallel with a switch, preferably an NFET N2, between N0 and ground. The switches are enabled during power-up, thereby providing quick turn-on of the oscillator. They are then disabled, thereby reducing the voltage across the crystal XTAL and consequently reducing the power consumed.

Abstract: A memory processor which prevents errors when the compiler advances long latency load instructions in the instruction sequence to reduce the loss of efficiency resulting from the latency time. The memory processor intercepts all load and store instructions prior to the instructions entering the memory pipeline. The memory processor stores load instructions for a period of time sufficient to determine if any subsequent store instruction that would have been executed prior to the load instruction, had the load instruction not been moved, references the same address as that specified in the load instruction. If a store instruction references the load instruction address, the invention returns the same data as the load instruction would have if it was not moved by the compiler.

Abstract: A circuit for detecting a system reset caused by the turning on of power supply of an electronic system. The circuit comprises: latch means coupled to said power supply having a SET input and an output, said output of said latch means being reset to a first predetermined state during power-on; feedback means for receiving said output from said latch means and said system reset, said feedback means activating its output when both of said first predetermined state from said latch means' output and said system reset are present; delay means coupled to the output from said feedback means and to said latch means, said delay means activating its output a predetermined time after said delay means receiving an activated output from said feedback means, said activated output from said delay means setting said latch means to a second predetermined state such that said feedback means remains de-activated when only said system reset is present without power-on.

Abstract: An oscillator circuit provides a symmetrical signal without halving the frequency of a crystal oscillator 12. The input 14 of the crystal oscillator 12 is low pass filtered, and the output 18 of the filter 16 is differential voltage compared with the input 14 of the crystal oscillator 12. The output 22 of the differential voltage comparator 20 is symmetrical and of the same frequency as the crystal oscillator 12. The crystal oscillator 12 is preferably a Pierce oscillator.

Abstract: An ESD protection circuit for the pads of an integrated circuit (IC) using silicide-clad diffusions is disclosed. The circuit uses a robust N+ diode with N-well block, an output NFET and a large transient clamp, each with a distributed, integrated N-well drain resistor to prevent the IC from avalanching and leakage during the Human Body Model and Charged Device Model tests for ESD.

Abstract: The improved cache system reduces the effects of latency times by utilizing a preload instruction inserted by the compiler into the code. The preload instruction is sent sufficiently in advance of the corresponding load instruction to guarantee that the relevant data is in the cache memory when the load instruction is received. In addition, the invention prevents the pollution of the cache with data that will only be used once during the expected lifetime of the data in the cache. This second feature of the invention assures that a large number of references to data that will only be used once does not result in the contents of the cache being replaced with the subsequent need to reload the contents after the data references have been completed.

Abstract: A method of synchronizing the parallel processors of a multiple instruction stream multiprocessor employs a limited number of register channels, which may be re-used, for enforcing cross-stream data or event dependencies by passing data or event notifications in a synchronizing fashion. Cross-stream dependencies which by virtue of identified "synchronization redundancey" do not require enforcement by register channels are passed by writing to and reading from ordinary shared memory. A compiling method schedules the instructions into parallel instruction streams by reference to a directed acyclic graph (DAG), in a manner to minimize the production of cross-stream dependencies. The scheduling is determined beginning from the highest nodes in the DAG and proceeding to nodes in order of descending node height in a manner tending and tends to assign whole sub-graphs of the DAG to different processors.

Abstract: Method for compiling program instructions to reduce instruction cache misses and instruction cache pollution. The program is analyzed for instructions which result in a non-sequential transfer of control in the program. The presence of branch instructions and program loops are identified and analyzed. The instructions are placed in lines, and the lines are placed in a sequence to minimize potential misses.

Abstract: A Multiple Instruction Stream Multiple Data Stream (MIMD) parallel processing apparatus and compiling method for effectuating collective branching of execution by the processors includes specialized branch and fuzzy barrier units which operate with respect to special instructions scheduled in unshaded regions of the instruction streams of the processors involved in a collective branch. A special compare instruction is scheduled in a first unshaded region of only one of the processors while a special jump instruction is scheduled in the next unshaded region of the instruction stream of the other involved processors. By the special jump instruction, the other processors use the special compare result which is simultaneously passed to each of them by the branch unit for determining the execution branch. The barrier unit provides fuzzy barrier synchronization assuring that the correct compare result is used in this determination.

Abstract: A circuit for use on an integrated circuit chip for detecting the operative connection of a crystal used to control an on-chip crystal controlled oscillator, which generates a cyclical clock signal, by detecting the presence or absence, respectively, of the cyclical clock signal and for providing an output control signal in response thereto to an on-chip terminal pad control circuit which automatically enables an on-chip terminal pad to be utilized as a clock signal output terminal pad if the cyclical clock signal presence is detected or as a clock signal input terminal pad otherwise. Also, a method of automatically switching the function of a terminal pad on an integrated circuit chip to function as a clock signal output terminal pad or as a clock signal input terminal pad in accordance with detecting the existence or non-existence of a cyclical clock signal generated on-chip.