Abstract: According to an apparatus form of the invention, integrated circuitry on a single chip includes a bit-programmable voltage regulator supplying voltage to first circuitry on the chip. The integrated circuitry also includes second circuitry operable for characterizing performance of the first circuitry. Control circuitry on the chip is operable, responsive to the characterizing performed by the second circuitry, to output at least one digital control bit for controlling the regulator output voltage supplying the first circuitry. In another aspect, the integrated circuitry is operable to receive an externally generated, time-based reference signal, and the second circuitry includes an on-chip oscillator for generating a performance characterizing signal. The performance characterizing signal varies in frequency in correspondence with the performance of the first circuitry.

Abstract: A method of reducing power consumption while maintaining performance characteristics and avoiding costly over-design of a high-speed communication link embedded in an SOC is provided. The method includes synthesizing the communication link at a reduced voltage to determine and isolate circuitry that is supply-voltage-critical from circuitry that is non-supply-voltage-critical. The supply-voltage-critical circuitry contains components that may not operate at the reduced voltage without degrading the performance characteristics of the communication link. A non-reduced voltage is used to drive the supply-voltage-critical circuitry while the reduced voltage is used to drive the non-supply-voltage-critical circuitry. The reduced voltage is generated using a voltage regulator embedded in the communication link.

Abstract: According to an apparatus form of the invention, integrated circuitry on a single chip includes a bit-programmable voltage regulator supplying voltage to first circuitry on the chip. The integrated circuitry also includes second circuitry operable for characterizing performance of the first circuitry. Control circuitry on the chip is operable, responsive to the characterizing performed by the second circuitry, to output at least one digital control bit for controlling the regulator output voltage supplying the first circuitry. In another aspect, the integrated circuitry is operable to receive an externally generated, time-based reference signal, and the second circuitry includes an on-chip oscillator for generating a performance characterizing signal. The performance characterizing signal varies in frequency in correspondence with the performance of the first circuitry.

Abstract: In one form of the invention, circuitry having exclusive-OR and latch functionality includes timing circuitry and logic circuitry. The circuitry includes a memory, with first and second memory nodes, for storing a state and its complement, and first and second timing circuitry portions, each operable to receive at least one timing signal, coupled to the respective memory nodes. The logic circuitry includes first and second logic circuitry portions, each of which is operable to receive at least first and second data signals. Each of the logic circuitry portions is coupled in series with a conditionally conductive path of one of the respective first and second timing circuitry portions.

Abstract: A level shifter having a data input node, a first inverter having its input connected to the data input node, a second inverter connected to an output of the first inverter, a data output node, a latch having its output connected to the data output node, a first NFET connected between an input of the latch and a ground potential, and having its gate electrode connected to an output of the second inverter, and a second NFET connected between the data output node and the ground potential, and having its gate electrode connected to the output of the first inverter. The level shifter provides for a conversion of a data signal from a power supply domain of 1.8 volts to one of 3.3 volts.

Abstract: A method of reducing power consumption while maintaining performance characteristics and avoiding costly over-design of a high-speed communication link embedded in an SOC is provided. The method includes synthesizing the communication link at a reduced voltage to determine and isolate circuitry that is supply-voltage-critical from circuitry that is non-supply-voltage-critical. The supply-voltage-critical circuitry contains components that may not operate at the reduced voltage without degrading the performance characteristics of the communication link. A non-reduced voltage is used to drive the supply-voltage-critical circuitry while the reduced voltage is used to drive the non-supply-voltage-critical circuitry. The reduced voltage is generated using a voltage regulator embedded in the communication link.

Abstract: A level shifter having a data input node, a first inverter having its input connected to the data input node, a second inverter connected to an output of the first inverter, a data output node, a latch having its output connected to the data output node, a first NFET connected between an input of the latch and a ground potential, and having its gate electrode connected to an output of the second inverter, and a second NFET connected between the data output node and the ground potential, and having its gate electrode connected to the output of the first inverter. The level shifter provides for a conversion of a data signal from a power supply domain of 1.8 volts to one of 3.3 volts.

Abstract: A level shifter having a data input node, a first inverter having its input connected to the data input node, a second inverter connected to an output of the first inverter, a data output node, a latch having its output connected to the data output node, a first NFET connected between an input of the latch and a ground potential, and having its gate electrode connected to an output of the second inverter, and a second NFET connected between the data output node and the ground potential, and having its gate electrode connected to the output of the first inverter. The level shifter provides for a conversion of a data signal from a power supply domain of 1.8 volts to one of 3.3 volts.

Abstract: A system and integrated circuit (die) including a clock generator that includes an on-chip inductor and uses the inherent capacitance of the load to generate a sinusoidal clock signal. The inductor is connected between a current source and an inverting switch. The output of the switch is a substantially sinusoidal signal that connected directly to at least a portion of the clock driven circuits without intermediate buffering. In the preferred embodiment, the clock generator is a dual phase design that includes a pair of cross-coupled MOSFET's, a pair of solid state on-chip inductors, and a current source. Each of the on-chip inductors is connected between the current source and the drain of one of the MOSFET's. The outputs of the clock generator are provided directly to the clock inputs of at least a portion of the clock driven circuits on the die.

Abstract: In one form of the invention, circuitry having exclusive-OR and latch functionality includes timing circuitry and logic circuitry. The circuitry includes a memory, with first and second memory nodes, for storing a state and its complement, and first and second timing circuitry portions, each operable to receive at least one timing signal, coupled to the respective memory nodes. The logic circuitry includes first and second logic circuitry portions, each of which is operable to receive at least first and second data signals. Each of the logic circuitry portions is coupled in series with a conditionally conductive path of one of the respective first and second timing circuitry portions.

Abstract: A condition code register architecture for supporting multiple execution units is disclosed. A master execution unit is coupled a master condition code register such that condition codes generated by the master execution unit are stored in the master condition code register. A non-master execution unit is coupled to a shadow condition code register such that condition codes generated by the non-master execution unit are stored in the shadow condition code register. A tag unit coupled to the master execution unit and the non-master execution unit such that an entry within the master condition code register can be read only when a corresponding entry within the tag unit is referenced to the master execution unit or the master condition code register.

Abstract: A processor that promotes accelerated resolution of conditional branch instructions includes an instruction sequencer that fetches a plurality of instructions and a detector that detects, among the plurality of fetched instructions, a condition-setting instruction and a conditional branch instruction that depends upon the condition-setting instruction. The processor further includes a decoder that decodes the conditional branch instruction to produce a decoded condition type and an execution unit. In response to the detection of the condition-setting instruction and the conditional branch instruction, the execution unit resolves the conditional branch instruction by evaluating the condition-setting instruction and the decoded condition type in a single operation. Because the condition code bits are not computed or stored as an intermediate result as in prior art processors, branch resolution is accelerated.

Abstract: A leading-zero anticipator having an independent sign bit determination module is disclosed. An apparatus for anticipating leading zeros for an adder within a floating-point processor includes a leading-zero anticipator and a sign determination module. The leading-zero anticipator generates a leading zeros string and a leading ones string by examining carry propagates, generates, and kills of two adjacent bits of two input operands of the adder. The leading zeros string is intended for a positive sum, and the leading ones string is intended for a negative sum. Independent of the leading-zero anticipator, the sign determination module determines a sign of the output of the adder in concurrence with the operations within the leading-zero anticipator.

Abstract: A five-input/two-output binary adder is disclosed. The five-input/two-output adder includes five inputs and two outputs. Four levels of XOR logic gates are coupled between the five inputs and the two outputs for combining values received at the five inputs and generating a sum value and a carry value at the outputs.

Abstract: In one aspect, a method for charge recovery in dynamic circuitry includes discharging a dynamic node during an evaluation interval by input circuitry coupled to the dynamic node responsive to one or more input signals. The discharging includes transferring the charge from the dynamic node to a capacitor during the evaluation time interval. The dynamic node is charged during a precharge interval by a voltage source and precharge timing circuitry coupled to the dynamic node responsive to a precharge signal. The charging includes transferring the charge from the capacitor back to the dynamic node.

Abstract: In one aspect, a method for a sleep mode in a dynamic circuit includes driving a dynamic node to an operating voltage state during a precharge interval by precharge timing circuitry coupled to the dynamic node and a voltage source responsive to a precharge signal. The dynamic node is selectively pulled to a low voltage state during an evaluation interval by input circuitry coupled to the dynamic node responsive to one or more input signals. The dynamic node voltage is inverted by output circuitry coupled to the dynamic node and to an output node. The output node is isolated from ground during a sleep interval responsive to a sleep signal by sleep circuitry coupled to the output circuitry.

Abstract: A method for generating shift amount signals for an alignment shifter is disclosed. In a process of adding a first floating-point number and a second floating-point number, wherein the floating-point numbers includes a sign, a mantissa, and an exponent, an alignment shifter is used to provide proper alignment for the floating-point numbers. Residue arithmetics are performed on an exponent of the first floating-point number and an exponent of the second floating-point number to generate a residue shift amount. The residue shift amount is then decoded to obtain shift amount signals that are readable by the alignment shifter.

Abstract: A voltage controlled oscillator (VCO) and phase-locked loop (PLL) topologies that allow for low-voltage, high frequency, low-jitter operation are disclosed. The conventional PLL design is modified so as to bifurcate the error signal into AC and DC components. A VCO accepting AC- and DC-component control inputs adjusts its output frequency in accordance with both inputs.

Abstract: In one aspect, a method for a sleep mode in a dynamic circuit includes driving a dynamic node to an operating voltage state during a precharge interval by precharge timing circuitry coupled to the dynamic node and a voltage source responsive to a precharge signal. The dynamic node is selectively pulled to a low voltage state during an evaluation interval by input circuitry coupled to the dynamic node responsive to one or more input signals. The dynamic node voltage is inverted by output circuitry coupled to the dynamic node and to an output node. The output node is isolated from ground during a sleep interval responsive to a sleep signal by sleep circuitry coupled to the output circuitry.

Abstract: In one aspect, a method for charge recovery in dynamic circuitry includes discharging a dynamic node during an evaluation interval by input circuitry coupled to the dynamic node responsive to one or more input signals. The discharging includes transferring the charge from the dynamic node to a capacitor during the evaluation time interval. The dynamic node is charged during a precharge interval by a voltage source and precharge timing circuitry coupled to the dynamic node responsive to a precharge signal. The charging includes transferring the charge from the capacitor back to the dynamic node.