Abstract: A method and apparatus are described for performing multiplication in a processor to generate a product. In one embodiment, a 64-bit multiplier and a 64-bit multiplicand may be multiplied together over four cycles by merging different partial product (PP) subsets, generated by a Booth encoder and a PP generator, with feedback sum and carry results. The logic inputs of a plurality of multiplexers may be selected on a cyclical basis to efficiently compress (i.e., merge) each PP subset with feedback sum and carry results. A pair of preliminary sum results stored during one cycle may be outputted during a subsequent cycle and processed by a logic gate (e.g., an XOR gate) to generate a feedback sum result that is merged with a feedback carry result and a PP subset. Final sum and carry results may be added to generate the product of the multiplier and the multiplicand.

Abstract: A clock driver for a resonant clock network includes a delay circuit that receives and supplies a delayed clock signal. A first transistor is coupled to receive a first pulse control signal and supply an output clock node of the clock driver. An asserted edge of the first control signal is responsive to the falling edge of the delayed clock signal. A second transistor is coupled to receive a second control signal and to supply the output clock node of the clock driver. An asserted edge of the second control signal is responsive to a rising edge of the delayed clock signal.

Abstract: A clock driver circuit supplies a clock signal with a drive strength determined according to one or more control signals supplied to the clock driver that vary during run-time. The clock driver is operated with a first drive strength in a non-resonant mode of operation of an associated clock network and with a second drive strength in a resonant mode of operation of the associated clock network, the first drive strength being higher than the second drive strength.

Abstract: A sense-amplifier monotizer includes an amplifier circuit and a keeper circuit. The amplifier circuit outputs a predetermined logic state while a clock signal is in a first phase, and samples a data signal and outputs at least one of the data signal and a complementary logic state of the data signal while the clock signal is in a second phase. A subsequent change of the data signal does not affect an output of the amplifier circuit once the data signal is sampled while the clock signal is in the second phase. The keeper circuit keeps a logic state of the sampled data signal once the data signal is sampled while the clock signal is in the second phase. The amplifier circuit may receive multiple data signals, and output a data signal selected by the select signal and/or a complementary value while the clock signal is in the second phase.

Abstract: A resonant clock network includes an inductor coupled to the clock network through a plurality of switches. When the clock network enters resonant mode, the turn-on of the switches to couple the inductor to the clock network is staggered. The clock network may be formed of multiple regions, each with its own inductor and switches. The turn-on of switches of each region may be staggered with respect to the turn-on off the switches of the other regions as well as to the turn-on of switches within a region. In addition to staggering the turn-on of the switches when entering the resonant mode, the switches may be turned off in a staggered manner when exiting the resonant mode of operation.

Abstract: A clock driver circuit supplies a clock signal with a drive strength determined according to one or more control signals supplied to the clock driver that vary during run-time. The clock driver is operated with a first drive strength in a non-resonant mode of operation of an associated clock network and with a second drive strength in a resonant mode of operation of the associated clock network, the first drive strength being higher than the second drive strength.

Abstract: A clock driver for a resonant clock network includes a delay circuit that receives and supplies a delayed clock signal. A first transistor is coupled to receive a first pulse control signal and supply an output clock node of the clock driver. An asserted edge of the first control signal is responsive to the falling edge of the delayed clock signal. A second transistor is coupled to receive a second control signal and to supply the output clock node of the clock driver. An asserted edge of the second control signal is responsive to a rising edge of the delayed clock signal.

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 are described for generating flags in response to processing data during an execution pipeline cycle of a processor. The processor may include a multiplexer configured generate valid bits for received data according to a designated data size, and a logic unit configured to control the generation of flags based on a shift or rotate operation command, the designated data size and information indicating how many bytes and bits to rotate or shift the data by. A carry flag may be used to extend the amount of bits supported by shift and rotate operations. A sign flag may be used to indicate whether a result is a positive or negative number. An overflow flag may be used to indicate that a data overflow exists, whereby there are not a sufficient number of bits to store the data.

Abstract: A method and apparatus are described for using a previous column pointer to read a subset of entries of an array in a processor. The array may have a plurality of rows and columns of entries, and each entry in the subset may reside on a different row of the array. A previous column pointer may be generated for each of the rows of the array based on a plurality of bits indicating the number of valid entries in the subset to be read, the previous column pointer indicating whether each entry is in a current column or a previous column. The entries in the subset may be read and re-ordered, and invalid entries in the subset may be replaced with nulls. The valid entries and nulls may then be outputted.

Abstract: A method and apparatus are described for processing data during an execution pipeline cycle of a processor. Valid bits of the data are generated according to a designated data size. Each of the valid bits is inserted into at least one of a plurality of bit positions. The valid bits are rotated in a predetermined direction (i.e., left or right rotation) by a designated number of bit positions. Valid bits are removed from a portion of the plurality of bit positions after being rotated. Zeros or most significant bits (MSBs) of the data may be inserted in the bit positions from which the valid bits were removed. The number of bit positions to rotate the valid bits by may be designated by a first bit subset and a second bit subset. The first bit subset may indicate a number of bytes, and the second bit subset may indicate a number of bits.

Abstract: A method and apparatus are described for performing multiplication in a processor to generate a product. In one embodiment, a 64-bit multiplier and a 64-bit multiplicand may be multiplied together over four cycles by merging different partial product (PP) subsets, generated by a Booth encoder and a PP generator, with feedback sum and carry results. The logic inputs of a plurality of multiplexers may be selected on a cyclical basis to efficiently compress (i.e., merge) each PP subset with feedback sum and carry results. A pair of preliminary sum results stored during one cycle may be outputted during a subsequent cycle and processed by a logic gate (e.g., an XOR gate) to generate a feedback sum result that is merged with a feedback carry result and a PP subset. Final sum and carry results may be added to generate the product of the multiplier and the multiplicand.

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 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 sense-amplifier monotizer includes an amplifier circuit and a keeper circuit. The amplifier circuit outputs a predetermined logic state while a clock signal is in a first phase, and samples a data signal and outputs at least one of the data signal and a complementary logic state of the data signal while the clock signal is in a second phase. A subsequent change of the data signal does not affect an output of the amplifier circuit once the data signal is sampled while the clock signal is in the second phase. The keeper circuit keeps a logic state of the sampled data signal once the data signal is sampled while the clock signal is in the second phase. The amplifier circuit may receive multiple data signals, and output a data signal selected by the select signal and/or a complementary value while the clock signal is in the second phase.

Abstract: Methods, systems, and apparatuses are presented that remove BIST intrusion logic from critical timing paths of a microcircuit design without significant impact on testing. In one embodiment, BIST data is multiplexed with scan test data and serially clocked in through scan test cells for BIST testing. In another embodiment, BIST data is injected into the feedback path of one or more data latches. In a third embodiment, BIST data is injected into the result data path of a multi-cycle ALU within an execution unit. In each embodiment, BIST circuitry is eliminated from critical timing paths.