Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A method for efficient logging in a control system is provided. A first plurality of registers, frequently accessed registers, is identified. A request is received from a server to access at least one of the first plurality of registers. The request includes a second plurality of registers and a plurality of data values to be stored in the second plurality of registers. At least some registers included in the request are frequently accessed registers. A third plurality of registers is identified based on predetermined criteria for inclusion. The third plurality of registers is a subset of the second plurality of registers storing a corresponding subset of the plurality of data values. A log entry is stored in an event log file corresponding to each data value included the third plurality of registers.

Abstract: A static random access memory (SRAM) includes a first port word line, a second port word line, a first port bit line and a first port complementary bit line, a second port bit line and second port complementary bit line, and a memory cell having a data node coupled to the first and second port bit lines and a complementary data node coupled to the first and second port complementary bit lines. The first and second port word lines control access to the dual port memory cell. A circuit couples the second port bit line to a high voltage supply node during a write logic high operation to the data node through the first port bit line and couple the second port complementary bit line to the high voltage supply node during a write logic high operation to the complementary data node through the first port complementary bit line.

Abstract: Synthesizable code representing first-in-first out (FIFO) memories may be used to produce FIFO memories in a hardware element or system. To more efficiently use a memory element that stores the data in a FIFO, a code generator may generate a wrapper that enables the FIFO to use a memory element with different dimension (i.e., depth and width) than the FIFO's dimensions. For example, the wrapper enables a 128 deep, 1 bit wide FIFO to store data in a memory element with 16 rows that store 8 bits each. To any system communicating with the FIFO, the FIFO behaves like a 128×1 FIFO even though the FIFO is implemented using a 16×8 memory element. To do so, the code generator may generate a wrapper which enables the folded memory element to behave like a memory element that was not folded.

Abstract: An object of the present invention is to provide a programmable logic device which has short start-up time after supply of power is stopped, is highly integrated, and operates with low power. In a programmable logic device including an input/output block, a plurality of logic blocks each including a logic element, and a wiring connecting the plurality of logic blocks, the logic element has a configuration memory for holding configuration data and a look-up table including a selection circuit. The configuration memory includes a plurality of memory elements each of which includes a transistor whose channel region is in an oxide semiconductor film and an arithmetic circuit provided between the transistor and the selection circuit. Configuration data is selectively changed and output by the selection circuit in accordance with an input signal.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: A system includes: an initial clock region; a first adjacent clock region adjacent to the initial clock region; a spine coupled to receive a clock signal from a clock; and a first phase detector coupled to detect a difference in phase between the initial clock region and the first adjacent clock region. The initial clock region comprises an initial delay element coupled to the spine and to the first phase detector.

Abstract: An embedded multimedia card (eMMC) communicating with a host includes; a latch circuit that receives and latches a data signal according to either a first edge or a second edge of a clock to thereby generate a latched data signal, and a start bit detector that detects in the latched data signal a start bit and provides a valid data signal from a portion of the latched data signal following the start bit.

Abstract: To optimize the arrangement of configuration data stored in a configuration memory. A lookup table includes a memory configured to store configuration data, a plurality of multiplexers each configured to select one signal from a plurality of input signals in accordance with the configuration data supplied from the memory and output the one signal, and an inverter. The plurality of multiplexers are connected in a binary tree with multiple levels. The inverter is provided between one of input terminals of a multiplexer in an uppermost level and an output terminal of a multiplexer in one level lower than the uppermost level. Signal selection is performed in each of the multiplexers so that the multiplexer in the uppermost level outputs, as an output signal, one signal of all input signals of the multiplexers in a lowermost level.

Abstract: Field programmable gate arrays using resistivity-sensitive memories are described, including a programmable cell comprising a configurable logic, a memory connected to the configurable logic to provide functions for the configurable logic, the memory comprises a non-volatile rewriteable memory element including a resistivity-sensitive memory element, an input/output logic connected to the configurable logic and the memory to communicate with other cells. The memory elements may be two-terminal resistivity-sensitive memory elements that store data in the absence of power. The two-terminal memory elements may store data as plurality of conductivity profiles that can be non-destructively read by applying a read voltage across the terminals of the memory element and data can be written to the two-terminal memory elements by applying a write voltage across the terminals.

Abstract: A method for testing and correcting a memory system is described. The method includes selecting a target memory unit of the memory system having a timing margin in response to a trigger to start a timing margin measurement. The stored data in the target memory unit is moved to a spare memory unit. The memory system performs reads and writes of user data from the spare memory unit while measuring the target memory unit. The timing margins of the target memory unit are measured. The reliability of the measured timing margins of the target memory unit based on a timing margin profile is determined.

Abstract: A system including a configurable memory controller, a memory interface, and a configurable high speed communications fabric comprising a plurality of interconnect stations arranged in an array and operable to implement a plurality of pipelined buses, where the configurable memory controller is operably coupled to the configurable high speed communications fabric using a first interconnect station of the plurality of interconnect stations, where the memory interface is operably coupled to the configurable high speed communications fabric using a second interconnect station of the plurality of interconnect stations, where the plurality of interconnect stations are configured to satisfy a timing requirement of the memory interface, and where the configurable memory controller, the memory interface, and the configurable high speed communications fabric are associated with a configurable integrated circuit.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: Some embodiments provide a circuit for accessing stored data in a configurable IC that includes several configurable circuits. The IC also includes several storage circuits. Each storage circuit has (1) several storage elements for storing data for the configurable circuits, and (2) output circuitry for outputting data stored in the storage elements. The output circuitry includes a first set of interconnects for receiving at least a first repeating periodic signal and for periodically outputting data from at least two storage elements to the configurable circuits.

Abstract: Methods and systems to stress-program a first integrated circuit (IC) block to output a pre-determined value upon activation/reset, such as to support time-zero compensation/trimming. To program, the first block is configured with first-block program parameters to cause the first block to output a pre-determined value. The first block is stressed while configured with the first-block program parameters, to cause the first block to output the pre-determined value without the first-block program parameters. The first block may include a latch designed as a fully balance circuit and may be asymmetrically stressed to alter a characteristic of one path relative to another. The pre-determined value may be selected to compensate for process corner variations and/or other random variations.

Abstract: A novel configurable integrated circuit (IC) that has several configurable circuits for configurably performing different operations is provided. During the operation of the IC, each particular configurable circuit performs a particular operation that is specified by a particular configuration data set for the particular configurable circuit. While the IC operates and a first set of configurable circuits performs a first set of operations, configuration data is loaded from the outside of the IC for configuring a second set of configurable circuits. The configurable IC includes a configuration network for rapid loading configuration data in the IC from outside of the IC. The configuration network is a pipelined network.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (“IC”). The configurable IC includes a set of configurable logic circuits for configurably performing a set of functions. The configurable IC also includes a set of configurable routing circuits for routing signals to and from the configurable circuits. During several operational cycles of the configurable IC, a set of data registers are defined by the configurable routing circuits. These data registers may be used wherever a flip-flop can be used.

Abstract: Aspects of the disclosure provide a clock gate circuit for generating a clock signal. The clock gate circuit includes a multiplexer and a logic module coupled to the multiplexer. The multiplexer is configured to receive a first logic signal at a first data input, a second logic signal at a second data input, and a reference clock signal at a selector input, and to output the clock signal having a logic state selected from one of the first logic signal or the second logic signal based on transitions of the reference clock signal. The logic module includes at least one of an XNOR and an XOR module and is configured to provide an output signal that is responsive to performing at least one of an XNOR and an XOR operation of the output of the multiplexer and an enable signal that enables or disables the clock gate circuit to generate the clock signal.

Abstract: An integrated circuit design protecting device includes a switch device and a non-volatile memory. The switch device includes M input ports, N output ports, N multiplexers, and S selection nodes. Each multiplexer of the N multiplexers includes I input nodes, an output node, and at least one selection node. The I input nodes are coupled to I input ports of the M input ports. The output node is coupled to an output port of the N output ports. The non-volatile memory is coupled to the S selection nodes of the switch device for providing selection codes to the switch device.

Abstract: A novel integrated circuit (IC) that configurably distributes clocks from multiple clock sources to multiple sets of circuits is described. The IC includes multiple clock sources and multiple clock domains. Each clock domain includes a clock signal and a control signal. The clock signal is configurably selected from one of the multiple clock sources. The control signal is synchronized to the clock signal. The IC also includes multiple configurable circuits. A configurable circuit can configurably operate in one of the clock domains by selecting and using the control signal and the clock signal of the clock domain.

Abstract: A logic processing device, containing an application specific integrated circuit (“ASIC”) and field programmable gate array (“FPGA”), capable of automatically interfacing between ASIC and FPGA is disclosed. The logic processing device, in one aspect, includes a phase adjustment circuit, ASIC, and configurable logic circuit (“CLC”) wherein the CLC can be an FPGA. While ASIC is able to perform a specific function in accordance with an ASIC clock domain, the CLC is capable of performing a programmable logic function in accordance with an FPGA clock domain. The phase adjustment circuit is used to automatically facilitate a communication between the ASIC and the CLC in accordance with the ASIC clock domain and the FPGA clock domain.

Abstract: To optimize the arrangement of configuration data stored in a configuration memory. A lookup table includes a memory configured to store configuration data, a plurality of multiplexers each configured to select one signal from a plurality of input signals in accordance with the configuration data supplied from the memory and output the one signal, and an inverter. The plurality of multiplexers are connected in a binary tree with multiple levels. The inverter is provided between one of input terminals of a multiplexer in an uppermost level and an output terminal of a multiplexer in one level lower than the uppermost level. Signal selection is performed in each of the multiplexers so that the multiplexer in the uppermost level outputs, as an output signal, one signal of all input signals of the multiplexers in a lowermost level.

Abstract: One embodiment relates to a circuit for pipelined direct-drive routing, the circuit including a routing multiplexer, a flip-flop, and a mode multiplexer. The output of the routing multiplexer is coupled to an input of the mode multiplexer and to the flip-flop. The output of the flip-flop is connected to another input of the mode multiplexer. The flip-flop may be directly connected to the routing multiplexer and the mode multiplexer, or, in an alternate embodiment, the flip-flop may be a member of a pipeline register pool. Another embodiment relates to a circuit for pipelined direct-drive routing which uses a pulse latch. Other embodiments relate to method for pipelined direct-drive routing which includes a degree of logical separation between logic elements and flip-flop elements. Another embodiment relates to a logic array block. Other embodiments, aspects, and features are also disclosed.

Abstract: A reconfigurable integrated circuit device includes a memory unit for storing configuration information. The memory unit has a nonvolatile memory transistor having a gate connected to a first wire, a first terminal connected to a second wire, and a second terminal connected to a third wire. The memory unit also includes a switch circuit connected to the third wire. The switch circuit alters the configuration of the integrated circuit device by, for example, opening and closing to make wiring connections or disconnections. The integrated circuit device additionally includes a data supply circuit for supplying bit data and a first power supply circuit for supplying voltages to the first wire for storing bit data in the first nonvolatile memory transistor and for storing bit data as a charge level on the third wire.

Abstract: To provide a PLD having a reduced circuit area and an increased operation speed. In the circuit structure, a gate of a transistor provided between an input terminal and an output terminal of a programmable switch element is in an electrically floating state in a period when a signal is input to the programmable switch element. The structure enables the voltage of a gate to be increased by a boosting effect in response to a signal supplied from programmable logic elements, suppressing a reduction in amplitude voltage. This can reduce a circuit area by a region occupied by a booster circuit such as a pull-up circuit and increase operation speed.

Abstract: Configuration is performed in accordance with a plurality of states when power supply voltage is supplied intermittently. At the time of start of supply of power supply voltage with configuration, a programmable logic device is sequentially changed into a first state where configuration data is not set in a configuration memory, a second state where the configuration memory is initialized, and a third state where the configuration data can be set in the configuration memory. At the time of start of supply of power supply voltage without configuration, the programmable logic device is sequentially changed into a fourth state where the configuration data is not set in the configuration memory and the third state. The first to fourth states are switched to any one of the states by control of a first state signal and a second state signal.

Abstract: Disclosed is a semiconductor device which is intended to reduce the total number of storage element blocks that constitute a desired logic circuit. The semiconductor device includes N address lines (N is an integer equal to two or more), N data lines, and a plurality of storage sections. Each of the storage sections includes an address decoder for decoding an address supplied via the N address lines to output a word select signal to word lines; and a plurality of storage elements which are connected to the word lines and the data lines, each store data that constitute a truth table, and input or output the data via the data lines in accordance with the word select signal supplied via the word lines. The semiconductor device is adapted such that the N address lines for the storage sections are connected to the respective data lines of other N ones of the storage sections, while the N data lines for the storage sections are connected to the respective address lines of other N ones of the storage sections.

Abstract: An integrated circuit (“IC”) having configurable logic circuits for configurably performing multiple different logic operations based on configuration data is provided. The IC includes a configurable routing fabric for configurably routing signals among configurable logic circuits. The configurable routing fabric includes a particular wiring path that connects an output of a source circuit to inputs of a destination circuit. The particular wiring path includes a first path and a second path that is parallel to the first path. The first and second paths are for configurably storing output signals of the source circuit. The first path connects to a first input of the destination circuit and the second path connects to a second input of the destination path.

Abstract: A semiconductor device capable of reconfiguration, including: a plurality of logic units which configure an array and are connected to each other, wherein each logic unit includes a pair of a first and a second memory cell units, each of the first and the second memory cell units operates as a logic element when truth value table data is written in, which is configured so that a logic calculation of an input value specified by a plurality of addresses is output to a data line, and/or operates as a connection element when truth value table data is written in, which is configured so that an input value specified by a certain address is output to a data line to be connected to an address of another memory cell unit, a latter stage of the first memory cell unit includes a sequential circuit which synchronizes with a clock, and the logic units include, for each pair of the first and the second memory cell units, a selection unit which selectively outputs an address to the first or the second memory cell unit in ac

Abstract: An integrated circuit (IC) is described. The IC includes a clock distribution network for distributing a clock signal. The IC includes a first sequential circuit having a clock input to receive the clock signal to generate an output. The output of the first sequential circuit is coupled to an input of a first logic group comprising combinatorial logic circuitry. The IC also includes first circuitry to compare logic states of the input and the output and to inhibit the clock signal from propagating to the clock input if the logic states are the same. The IC also includes a second sequential circuit having a second clock input to receive the clock signal to generate a second output. The second output of the second sequential circuit is coupled to an input of a second logic group comprising combinatorial logic circuitry.

Abstract: A die-stacked memory device incorporates a reconfigurable logic device to provide implementation flexibility in performing various data manipulation operations and other memory operations that use data stored in the die-stacked memory device or that result in data that is to be stored in the die-stacked memory device. One or more configuration files representing corresponding logic configurations for the reconfigurable logic device can be stored in a configuration store at the die-stacked memory device, and a configuration controller can program a reconfigurable logic fabric of the reconfigurable logic device using a selected one of the configuration files. Due to the integration of the logic dies and the memory dies, the reconfigurable logic device can perform various data manipulation operations with higher bandwidth and lower latency and power consumption compared to devices external to the die-stacked memory device.

Abstract: A processor includes a programmable logic circuit provided with a plurality of processing units. The programmable logic circuit is capable of reconfiguring a first logic circuit corresponding to first circuit configuration information according to a first process and a second logic circuit corresponding to second circuit configuration information according to a second process. Each of the first and second logic circuits includes an information holding unit. A first control circuit stores the second circuit configuration information in the information holding unit of the first logic circuit and generates an execution control signal for executing the first process. A second control circuit obtains the second circuit configuration information from the information holding unit of the first logic circuit in response to completion of the first process and controls the programmable logic circuit so as to reconfigure the second logic circuit corresponding to the second circuit configuration information.

Abstract: A configurable logic block (CLB) and an operation method of the CLB are provided. The CLB includes memory units and a selecting circuit. The memory unit includes a first resistive non-volatile memory (RNVM) element and a second RNVM element. Top electrodes (TEs) of the first and second RNVM elements are coupled to an output terminal of the memory unit. Bottom electrodes (BEs) of the first and second RNVM elements are respectively coupled to a first bias terminal and a second bias terminal of the memory unit. The selecting circuit selects one of the memory units according to an input logic value and determines an output logic value of the CLB according to an output logic value of the selected memory unit.

Abstract: A circuit includes a summation circuit for receiving an input data signal and a feedback signal including a previous data bit. The summation circuit is configured to output a conditioned input data signal to a clock and data recovery circuit. A first flip-flop is coupled to an output of the summation circuit and is configured to receive a first set of bits of the conditioned input data signal and a first clock signal having a frequency that is less than a frequency at which the input data signal is received by the first summation circuit. A second flip-flop is coupled to the output of the summation circuit and is configured to receive a second set of bits of the conditioned input data signal and a second clock signal having a frequency that is less than the frequency at which the input data signal is received by the first summation circuit.

Abstract: Integrated circuits such as programmable integrated circuits may include programmable logic regions that can be configured to perform custom functions. Interconnects may be used to route signals throughout the integrated circuit. The programmable logic regions may have input selection circuitry for selecting and providing input signals from the interconnects to the programmable logic regions. The programmable logic regions may include look-up table circuitry for processing the input signals and registers for storing output signals from the look-up table circuitry. The programmable logic regions may include output selection circuitry for selecting which output signals are provided to output circuitry of the programmable logic regions. The programmable logic regions may include bypass paths that provide direct access to the registers from the interconnects by bypassing the input and output selection circuitry.

Abstract: A system on chip (SoC) has a nonvolatile memory array of n rows by m columns coupled to one or more of the core logic blocks. M is constrained to be an odd number. Each time a row of m data bits is written, parity is calculated using the m data bits. Before storing the parity bit, it is inverted. Each time a row is read, parity is checked to determine if a parity error is present in the recovered data bits. A boot operation is performed on the SoC when a parity error is detected.

Abstract: A latch circuit switches a differential operation performed by a differential operation circuit including a first logic circuit, a second logic circuit, a third logic circuit, and a fourth logic circuit and a single end operation performed by a single end operation circuit according to a logic level of an inputted selection signal. The latch circuit performs an operation to output an input signal and an inverted input signal without change from a first output terminal and a second output terminal of the latch circuit, respectively, and an operation to set the input signal and the inverted input signal in a hold state in the differential operation and performs an operation to output the input signal from the first output terminal without change and an operation to set the input signal in a hold state in the single end operation, according to a clock signal and an inverted clock signal.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (“IC”). The configurable IC includes a set of configurable logic circuits for configurably performing a set of functions. The configurable IC also includes a set of configurable routing circuits for routing signals to and from the configurable circuits. During several operational cycles of the configurable IC, a set of data registers are defined by the configurable routing circuits. These data registers may be used wherever a flip-flop can be used.

Abstract: A data transmission device includes a control unit and a delay chain unit. The control unit outputs a first control signal through an nth control signal, where n is a natural number. The delay chain unit includes a first switching element through an nth switching element. The switching elements receive a first data signal through an nth data signal and perform pipelining operations on the first through nth data signals based upon the first through nth control signals, respectively, to output the pipelined data signals as at least one data stream. The switching elements are connected to each other to form at least one data delay chain.

Abstract: An apparatus relating generally to an analog multiplexer is disclosed. In such an apparatus, the analog multiplexer has first select circuits and at least one second select circuit. The first select circuits have respective input nodes and output nodes. The output nodes are all coupled to one another to provide an output node of the analog multiplexer. The first select circuits are coupled to a first supply voltage of a first supply domain. The at least one second select circuit is coupled to a second supply voltage of a second supply domain different from the first supply domain. The at least one second select circuit has an input port and an output port. The output port is coupled to an input node of the input nodes.

Abstract: Integrated circuits may include memory interface circuitry that communicates with memory. The memory interface circuitry may include latch circuitry that receives a data strobe enable signal from the memory controller and latches the data strobe enable signal using a data strobe signal received from the memory. The integrated circuit may include logic circuitry that gates the data strobe signal using the latched data strobe enable signal. The logic circuitry may pass the data strobe signal in response to activation of the latched data strobe enable signal. The integrated circuit may include counter circuitry that monitors the gated data strobe signal. The counter circuitry may monitor the gated data strobe signal by counting pulses in the gated data strobe signal to produce a counter value. When the counter value reaches a target value, the logic circuitry may block the data strobe signal from passing to the memory controller.

Abstract: In accordance with one aspect of the invention, a hole is formed within an LE array of a PLD by interrupting the LE array base signal routing architecture such that a hole is left for IP function block to be incorporated. An interface region is provided for interfacing the remaining LE array base signal routing architecture to the IP function block.

Abstract: Apparatuses for reducing power consumption in a programmable logic device (PLD) with a self power down mechanism are disclosed. Methods and a machine readable medium for restoring a prior known state are provided. The prior known state is stored in a memory module before the PLD is powered down and the same state is restored from the memory module when the PLD is powered up. The memory module may be an internal or an external non-volatile or volatile memory source. One sector of the memory may be used to store the previous known state. The memory sector can be partitioned into different sections. One section may be used as a header section associated with a data storage section. Partitioning the memory sector into different sections and utilizing multiple addresses from each section ensure less read and write cycles during the powering down and the powering up of the PLD.

Abstract: Some embodiments provide a circuit for accessing stored data in a configurable IC that includes several configurable circuits. The IC also includes several storage circuits. Each storage circuit has (1) several storage elements for storing data for the configurable circuits, and (2) output circuitry for outputting data stored in the storage elements. The output circuitry includes a first set of interconnects for receiving at least a first repeating periodic signal and for periodically outputting data from at least two storage elements to the configurable circuits.

Abstract: A system and method for utilizing multiple configurable lanes for clock and data transfer in source synchronous systems that may utilize a clock signal from another source for interpreting data received from the source. In an embodiment, a system may include a transmitter configured to transmit at least one clock signal and at least one data signal to a receiver device. The receiver device may have at least one clock lane and at least one data lane for receiving signals from the transmitter device. The clock lane(s) and data lane(s) can be arranged in any order as per requirement of system design. In the receiver, after manufacture, each data lane may be configured to be clocked by any clock lane.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (“IC”). The configurable IC includes a set of configurable logic circuits for configurably performing a set of functions. The configurable IC also includes a set of configurable routing circuits for routing signals to and from the configurable circuits. During several operational cycles of the configurable IC, a set of data registers are defined by the configurable routing circuits. These data registers may be used wherever a flip-flop can be used.

Abstract: A method for designing a system on a target device includes assigning resources on the target device to static logic modules and partial reconfigurable (PR) modules in the system. The instances of one of the PR modules are placed and routed in parallel utilizing resources from those that are assigned. Other embodiments are also disclosed.

Abstract: A programmable analog device and an analog device that can retain data even when supply of a power supply potential is interrupted and consumes less power. In a semiconductor device, first to fourth transistors are used as switches in a unit cell including an analog element, and the output of the unit cell switches between a conducting state, a non-conducting state, and a conducting state through the analog element by controlling the potential of a first node where the first transistor and the second transistor are connected and the potential of a second node where the third transistor and the fourth transistor are connected.

Abstract: Aspects of the invention provide for improving a success rate of an engineering design change (ECO) for an integrated circuit. In one embodiment, aspects of the invention include a method for improving a success rate of an engineering design change (ECO) for an integrated circuit, including: identifying a plurality of spare latches within the integrated circuit; determining an input driver for each of the spare latches; and replacing each input driver with a programmable gate array, such that the programmable gate array is programmed to a functionality of the input driver.

Abstract: When a first sub-circuit of a programmable integrated circuit (“IC”) is to be deactivated, a global write enable (GWE) signal is deasserted. In response to deassertion of the GWE signal and a first memory cell associated with the first sub-circuit being in a first state, flip-flops in the first sub-circuit are disabled from changing state. In response to memory cells associated with sub-circuits other than the first sub-circuit being in a second state, flip-flops in the other sub-circuits are enabled to change state. When the first sub-circuit is to be activated, the GWE signal is asserted. Logic implemented by the first sub-circuit is preserved between the deasserting and the asserting of the GWE signal. In response to assertion of the GWE signal and the first memory cell associated with the first sub-circuit being in the first state, flip-flops in the first sub-circuit are enabled to change state.