Abstract: An apparatus including a JTAG interface, synchronous bus optimizer, core clocks generator, synchronous strobe driver, and a DLL. The JTAG interface receives control information indicating a first amount to advance a synchronous data strobe associated with a first data group and a second amount to delay a data bit signal associated with a second data group. The synchronous bus optimizer receives the control information, and develops a first value on a first ratio bus that indicates the first amount and a second value on a second ratio bus that indicates the second amount. The core clocks generator advances a data strobe clock by the first amount. The synchronous strobe driver employs the data strobe clock to generate the synchronous data strobe, where the synchronous data strobe, when enabled, is advanced also by the first amount. The DLL generates a delayed data bit signal, delayed by the second amount.

Abstract: An apparatus includes a Joint Test Action Group (JTAG) interface, a synchronous bus optimizer, a core clocks generator, and a synchronous strobe driver. The JTAG interface is configured to receive control information over a standard JTAG bus, where the control information indicates an amount to advance a synchronous data strobe associated with a data group. The synchronous bus optimizer is configured to receive the control information, and is configured to develop a value on a ratio bus that indicates the amount. The core clocks generator is coupled to the ratio bus and is configured to advance a data strobe clock by the amount. The synchronous strobe driver is configured to receive the data strobe clock, and is configured to employ the data strobe clock to generate the synchronous data strobe, where the synchronous data strobe, when enabled, is advanced also by the amount.

Abstract: An apparatus is provided that compensates for misalignment on a synchronous data bus. The apparatus includes a Joint Test Action Group (JTAG) interface, a synchronous bus optimizer, and a delay-locked loop (DLL). The JTAG interface is configured to receive control information over a standard JTAG bus, where the control information indicates an amount to delay a data bit signal associated with a data group. The synchronous bus optimizer is configured to receive the control information, and is configured to develop a value on a ratio bus that indicates the amount. The DLL is coupled to the ratio bus, and is configured generate a delayed data bit signal, where the DLL adds the amount of delay to the data bit signal to generate the delayed data bit signal.

Abstract: An apparatus that compensates for misalignment on a synchronous data bus, including a resistor network, a transmitting device, and a receiving device. The resistor network indicates an amount to advance a synchronous data strobe associated with a data group. The transmitting device has a core clocks generator and a synchronous strobe driver. The core clocks generator advances a data strobe clock by the amount. The synchronous strobe driver employs the data strobe clock to generate the synchronous data strobe, where the synchronous data strobe is advanced also by the amount. The receiving device has a composite delay element and delay-locked loops (DLLs). The composite delay element equalizes delay paths within the receiving device, where the delay paths correspond to the synchronous data strobe that is received from the transmitting device.

Abstract: An apparatus is provided that compensates for misalignment on a synchronous data bus. The apparatus includes a resistor network, a composite delay element, and delay-locked loops (DLLs). The resistor network is configured to provide a ratio signal that indicates an amount to delay data bit signals associated with a data group. The composite delay element is configured to equalize delay paths within a receiving device, where the delay paths correspond to a data strobe signal that is received from a transmitting device. The DLLs are coupled to the ratio signal and disposed within the receiving device, and are configured to generate delayed data bit signals, where the DLLs add the amount of delay to the data bit signals to generate the delayed data bit signals.

Abstract: An apparatus is provided that compensates for misalignment on a synchronous data bus. The apparatus includes a resistor network and a delay-locked loop (DLL). The resistor network is configured to provide a ratio signal that indicates an amount to delay a data bit signal associated with a data group. The DLL is coupled to the ratio signal, and is configured generate a delayed data bit signal, where the DLL adds the amount of delay to the data bit signal to generate the delayed data bit signal.

Abstract: A microprocessor includes a first plurality of fuses, a predetermined number of which are selectively blown. Control values are provided from the fuses to circuits of the microprocessor to control operation thereof. A second plurality of fuses are blown with the predetermined number of the first plurality of fuses that are blown and a Boolean complement of the predetermined number. In response to being reset, the microprocessor: reads the predetermined number and the Boolean complement of the predetermined number from the second plurality of fuses, Boolean complements the predetermined number read from the second plurality of fuses to generate a result, compares the result with the Boolean complement of the predetermined number read from the second plurality of fuses, and prevent itself from fetching and executing user program instructions if the result does not equal the Boolean complement of the predetermined number read from the second plurality of fuses.

Abstract: A microprocessor includes a first plurality of fuses, a predetermined number of which are selectively blown. Control values are provided from the first plurality of fuses to circuits of the microprocessor to control operation of the microprocessor. The microprocessor also includes a second plurality of fuses, blown with the predetermined number of the first plurality of fuses that are blown. In response to being reset, the microprocessor is configured to: read the first plurality of fuses and count a number of them that are blown; read the predetermined number from the second plurality of fuses; compare the counted number with the predetermined number read from the second plurality of fuses; and prevent itself from fetching and executing user program instructions if the number counted from reading the first plurality of fuses does not equal the predetermined number read from the second plurality of fuses.

Abstract: Microprocessors with multi-core dies that include bypass buses are provided. Each microprocessor comprises a plurality of physical pins for coupling the microprocessor to a processor bus coupled to a chipset. The multi-core die has at least two complementary sets of one or more processing cores, each providing a bus interface coupling respective core inputs and outputs to corresponding processor bus lines. A bypass bus on the die enables cores of the complementary sets to bypass the processor bus and communicate directly with each other. The bypass bus does not carry signals off the die, drive signals on the processor bus to the chipset, or receive chipset-drive signals from the processor bus. Moreover, the microprocessor is operable to detect whether the chipset or a complementary core is driving the processor bus, and if the latter, to select the higher quality bypass bus signals over the corresponding processor bus signals.

Abstract: A multi-core bus termination apparatus includes a location array and a plurality of drivers. The location array generates a plurality of location signals that indicate locations on the bus of a corresponding plurality of nodes that are coupled to the bus, where the locations comprise either an internal location or a bus end location. Each of the plurality of drivers has one of the corresponding plurality of nodes, and controls how the one of the corresponding plurality of nodes is driven responsive to a state of a corresponding one of the plurality of location signals. Each of the plurality of drivers has configurable multi-core logic. The configurable multi-core logic enables pull-up logic and first pull-down logic if the state indicates the bus end location. The configurable multi-core logic disables the pull-up logic and to enable the first pull-down logic and second pull-down logic if the state indicates the internal location.

Abstract: A core configuration discovery method and corresponding microprocessor are provided that does not rely on off-core logic or queries by system BIOS. Reset microcode is provided in the microprocessor's cores. Upon reset, the microcode queries and/or receives from other cores configuration-revealing information and collects the configuration-revealing information to determine a composite core configuration for the microprocessor. The composite core configuration may reveal the number of enabled cores, identify the enabled cores, reveal a hierarchical coordination system of the multi-core processor, such as a nodal map of the cores for certain inter-core communication processes or restricted activities, identify various domains and domain masters within such a system, and/or identify resources, such as voltage sources, clock sources, and caches, shared by various domains of the microprocessor. The composite core configuration may be used for power state management, reconfiguration, and other purposes.

Abstract: A multi-core processor provides a configurable resource shared by two or more cores, wherein configurations of the resource affect the power, speed, or efficiency with which the cores sharing the resource are able to operate. Internal core power state management logic configures each core to participate in a de-centralized inter-core power state discovery process to discover a composite target power state for the shared resource that is a most restrictive or power-conserving state that will not interfere with any of the corresponding target power states of each core sharing the resource. The internal core power state management logic determines whether the core is a master core authorized to configure the resource, and if so, configures that resource in the discovered composite power state. The de-centralized power state discovery process is carried out between the cores on sideband, non-system bus wires, without the assistance of centralized non-core logic.

Abstract: A first reticle set designed for manufacturing dies with a limited number of cores is modified into a second reticle set suitable for manufacturing at least some dies with at least twice as many cores. The first reticle set defines scribe lines to separate the originally defined dies. At least one scribe line is removed from pairs of adjacent but originally distinctly defined dies. Inter-core communication wires are defined to connect the adjacent cores, which are configured to enable the adjacent cores to communicate during operation without connecting to any physical input/output landing pads of the resulting more numerously cored die, which will not carry signals through the inter-core communication wires off the P-core die. The inter-core communication wires may be used for power management coordination purposes or to bypass the external processor bus.

Abstract: Microprocessors are provided with decentralized logic and associated methods for indicating power related operating states, such as desired voltages and frequency ratios, to shared microprocessor power resources such as a voltage regulator module (VRM) and phase locked loops (PLLs). Each core is configured to generate a value to indicate a desired operating state of the core. Each core is also configured to receive a corresponding value from each other core sharing the applicable resource, and to calculate a composite value compatible with the minimal needs of each core sharing the applicable resource. Each core is further configured to conditionally drive the composite value off core to the applicable resource based on whether the core is designated as a master core for purposes of controlling or coordinating the applicable resource. The composite value is supplied to the applicable shared resource without using any active logic outside the plurality of cores.

Abstract: A multi-core processor includes microcode distributed in each core enabling each core to participate in a de-centralized inter-core state discovery process. In a related microcode-implemented method, states of a multi-core processor are discovered by at least two cores participating in a de-centralized inter-core state discovery process. The inter-core state discovery process is carried out through a combination of microcode executing on each participating core and signals exchanged between the cores through sideband non-system-bus communication wires. The discovery process is unmediated by any centralized non-core logic. Applicable discoverable states include target and composite power states, whether and how many cores are enabled, the availability and distribution of various resources, and hierarchical structures and coordination systems for the cores.

Abstract: An apparatus for dynamically varying a bias voltage that is applied to a substrate of an integrated circuit. The apparatus includes an adaptive bias generator, a state processor, and a fuse array. The adaptive bias generator is disposed on the integrated circuit, and is configured to generate a variable bias voltage according to a value received over a bias bus, where the variable bias voltage is applied to the substrate. The state processor is coupled to the adaptive bias generator, and is configured to receive one or more power management states, and is configured to provide the value over the bias bus, where the value is a function of the one or more power management states. The fuse array is operatively coupled to the state processor, and is configured to control one or more weighting values, where the weighting values are employed by the function to provide the value.

Abstract: An apparatus for dynamically varying a bias voltage that is applied to a substrate of an integrated circuit is provided. The apparatus includes a selective bias generator and state table logic. The selective bias generator is disposed on the integrated circuit and is configured to generate one of a plurality of bias voltages according to a value received over a bias select bus, where the one of the plurality of bias voltages is applied to the substrate. The state table logic is coupled to the selective bias generator, and is configured to receive one or more power management states, and is configured to provide the value over the bias select bus, where the value includes one of a plurality of bias indications stored within the state table logic.

Abstract: An apparatus includes an adaptive bias generator and a state processor. The adaptive bias generator is disposed on the integrated circuit, and is configured to generate a variable bias voltage according to a value received over a bias bus, where the variable bias voltage is applied to the substrate. The state processor is coupled to the adaptive bias generator, and is configured to receive one or more power management states, and is configured to provide the value over the bias bus, where the value is a function of the one or more power management states.

Abstract: A microprocessor that performs adaptive power throttling includes a calculation unit configured to calculate an average power consumed by the microprocessor over a most recent predetermined sample time and to determine whether the average power is less than a predetermined maximum power value. A power management unit controls the microprocessor to conditionally operate at a predetermined frequency if the average power is less than the predetermined maximum power value. The predetermined frequency is a frequency at which the microprocessor may consume more than the predetermined maximum power value. The power management unit controls the microprocessor to operate at the predetermined frequency only if the microprocessor was most recently instructed by system software to operate at a highest frequency instructable by the system software. The highest frequency instructable by the system software is less than the predetermined frequency.

Abstract: A microprocessor that performs adaptive power throttling includes a calculation unit that calculates an average power consumed by the microprocessor over a most recent predetermined sample time and determines whether the average power is less than a predetermined maximum power value. A power management unit controls the microprocessor to conditionally operate at a predetermined frequency if the average power is less than the predetermined maximum power value. The predetermined frequency is a frequency at which the microprocessor may consume more than the predetermined maximum power value. The predetermined maximum power value and sample time are specified to achieve power and/or thermal design goals of a system in which the microprocessor operates. The predetermined maximum power and/or sample time values are programmable by system software.