Abstract: A method for comparing content addressable memory (CAM) elements is disclosed. Binary values are stored in a pair of CAM elements. A comparison value is provided to a group of comparators, the comparison value based on the binary value stored in the pair of CAM elements. A match value is provided to the group of comparators, the match value corresponding to a binary value pair to be compared with the binary value stored in the pair of CAM elements. A positive match result value is output from a selected group of comparators via an output line in response to the comparison value matching the match value.

Abstract: A method and processor are described for implementing programmable priority encoding to track relative age order of operations in a scheduler queue. The processor may comprise a scheduler queue configured to maintain an ancestry table including a plurality of consecutively numbered row entries and a plurality of consecutively numbered columns. Each row entry includes one bit in each of the columns. Pickers are configured to pick an operation that is ready for execution based on the age of the operation as designated by the ancestry table. The column number of each bit having a select logic value indicates an operation that is older than the operation associated with the number of the row entry that the bit resides in.

Abstract: Content-Addressable Memory (CAM) arrays and related circuitry for integrated circuits and CAM array comparison methods are provided such that relatively low power is used in the operation of the CAM circuitry. A binary value pair is stored in a pair of CAM memory elements. A comparison signal is provided to comparator circuitry that uniquely represents the stored binary values. A match signal is input to the comparator circuitry that uniquely represents a binary value pair to be compared with the stored binary value pair. In one example, a transistor is operated to output a positive match result signal only on a condition that the comparison signal provided to the comparator circuitry and match signal input to the comparator circuitry represent the same binary value pair. In that example, no transistor of the comparator circuitry is operated when the comparison signal provided to the comparator circuitry and match signal input to the comparator circuitry represent different binary value pairs.

Abstract: A complementary metal oxide semiconductor (CMOS) circuit is described. The CMOS circuit includes a plurality of CMOS gates, a plurality of logic inputs and a logic output. Each CMOS gate is connected to a negative power supply terminal (Vss) and a positive power supply terminal (Vdd). The CMOS circuit further includes parasitic nets connected to the CMOS gates, and net pulldown circuits for eliminating a charge accumulation on the parasitic nets while avoiding potential short circuit conditions. The CMOS gates may be OR-AND-INVERT (OAI) gates or AND-OR-INVERT (AOI) gates.

Abstract: A method for picking an instruction for execution by a processor includes providing a multiple-entry vector, each entry in the vector including an indication of whether a corresponding instruction is ready to be picked. The vector is partitioned into equal-sized groups, and each group is evaluated starting with a highest priority group. The evaluating includes logically canceling all other groups in the vector when a group is determined to include an indication that an instruction is ready to be picked, whereby the vector only includes a positive indication for the one instruction that is ready to be picked.

Abstract: A method for comparing content addressable memory (CAM) elements is disclosed. Binary values are stored in a pair of CAM elements. A comparison value is provided to a group of comparators, the comparison value based on the binary value stored in the pair of CAM elements. A match value is provided to the group of comparators, the match value corresponding to a binary value pair to be compared with the binary value stored in the pair of CAM elements. A positive match result value is output from a selected group of comparators via an output line in response to the comparison value matching the match value.

Abstract: A complementary metal oxide semiconductor (CMOS) circuit is described. The CMOS circuit includes a plurality of CMOS gates, a plurality of logic inputs and a logic output. Each CMOS gate is connected to a negative power supply terminal (Vss) and a positive power supply terminal (Vdd). The CMOS circuit further includes parasitic nets connected to the CMOS gates, and net pulldown circuits for eliminating a charge accumulation on the parasitic nets while avoiding potential short circuit conditions. The CMOS gates may be OR-AND-INVERT (OAI) gates or AND-OR-INVERT (AOI) gates.

Abstract: A method and processor are described for implementing programmable priority encoding to track relative age order of operations in a scheduler queue. The processor may comprise a scheduler queue configured to maintain an ancestry table including a plurality of consecutively numbered row entries and a plurality of consecutively numbered columns. Each row entry includes one bit in each of the columns. Pickers are configured to pick an operation that is ready for execution based on the age of the operation as designated by the ancestry table. The column number of each bit having a select logic value indicates an operation that is older than the operation associated with the number of the row entry that the bit resides in.

Abstract: A method and apparatus for testing a content addressable memory (CAM) array includes writing known data to the CAM array and providing comparison data to the CAM array. A determination is made whether the CAM array is operating correctly responsive to a comparison of the known data and the comparison data.

Abstract: A method and apparatus for scheduling execution of instructions in a multi-issue processor. The apparatus includes post wake logic circuitry configured to track a plurality of entries corresponding to a plurality of instructions to be scheduled. Each instruction has at least one associated source address and a destination address. The post wake logic circuitry is configured to drive a ready input indicating an entry that is ready for execution based on a current match input. A picker circuitry is configured to pick an instruction for execution based the ready input. A compare circuit is configured to determine the destination address for the picked instruction, compare the destination address to the source address for all entries and drive the current match input.

Abstract: Content-Addressable Memory (CAM) arrays and related circuitry for integrated circuits and CAM array comparison methods are provided such that relatively low power is used in the operation of the CAM circuitry. A binary value pair is stored in a pair of CAM memory elements. A comparison signal is provided to comparator circuitry that uniquely represents the stored binary values. A match signal is input to the comparator circuitry that uniquely represents a binary value pair to be compared with the stored binary value pair. In one example, a transistor is operated to output a positive match result signal only on a condition that the comparison signal provided to the comparator circuitry and match signal input to the comparator circuitry represent the same binary value pair. In that example, no transistor of the comparator circuitry is operated when the comparison signal provided to the comparator circuitry and match signal input to the comparator circuitry represent different binary value pairs.

Abstract: A method and apparatus for protecting dynamic logic circuits from the effects of noise at the inputs to the dynamic logic circuits is disclosed. Parallel current flow or evaluate paths which couple an output node through a common node to a low voltage or ground rail include extra transistors in the current flow or evaluate path to allow the inputs to be protected while maintaining the operation and integrity of the circuit.

Abstract: A new self clocking family of dynamic logic gates which replace footless or subsequent stage dynamic logic gates in multi-stage domino logic circuits. In a preferred embodiment, a multi-stage logic circuit is designed having a first stage which utilizes a traditional dynamic logic gate and a second stage which includes a new self-clocking dynamic logic gate. The output from the first stage is coupled to the input of the second stage such that the second stage is not dependent upon any type of clock signal for precharging. Instead, the second stage includes a dual transistor arrangement on the inter-stage inputs (i.e. the outputs from one stage which are input to subsequent stages) in order to precharge the output node at the second stage such that no type of clock signal is needed during precharge. Accordingly, the output from the second stage is efficiently precharged without using a delayed clock signal or any customized delay circuitry while minimizing through current by design.

Abstract: A method and apparatus for protecting dynamic logic circuits from the effects of noise at the inputs to the dynamic logic circuits is disclosed. Parallel current flow or evaluate paths which couple an output node through a common node to a low voltage or ground rail include extra transistors in the current flow or evaluate path to allow the inputs to be protected while maintaining the operation and integrity of the circuit.

Abstract: A static latch includes two individual data paths. A first data path is used for passing the data on an output driver for driving a voltage level at the output from the latch toward a logic high or logic low voltage level depending upon the data. A second data path is used for storing the data in a feedback sturcutre so the latch can continue to drive the voltage level at the output node until the next data is loaded into the latch.

Abstract: An apparatus for high speed signal propagation across a net in an integrated circuit operates with a driver that is coupled to the net, for driving signals across the net. A first transition assist driver (TAD) is coupled to a first node in the net and is capable of pulling the voltage level of the first node in response to the voltage level of the first node reaching a threshold value. The threshold value can be adjusted in order to increase the switching speed or, alternatively, the noise immunity of the first TAD. A second TAD is coupled to a second node in the net and is capable of pulling the voltage level of the second node in response to the voltage level of the second node reaching the threshold value. The apparatus is used for increasing the propagation speed of signals that are transmitted in a microprocessor block or other stages in an integrated circuit.