Abstract: A branch target address cache (BTAC) caches history information associated with branch and switch key instructions previously executed by a microprocessor. The history information includes a target address and an identifier (index into a register file) for identifying key values associated with each of the previous branch and switch key instructions. A fetch unit receives from the BTAC a prediction that the fetch unit fetched a previous branch and switch key instruction and receives the target address and identifier associated with the fetched branch and switch key instruction. The fetch unit also fetches encrypted instruction data at the associated target address and decrypts (via XOR) the fetched encrypted instruction data based on the key values identified by the identifier, in response to receiving the prediction. If the BTAC predicts correctly, a pipeline flush normally associated with the branch and switch key instruction is avoided.

Abstract: An apparatus having a carryless preformat unit, a Booth encoder, a compressor, a left shifter, and exclusive-OR logic. The carryless preformat unit receives a multiplier operand and partitions the multiplier operand into parts. The Booth encoder receives the parts and directs selection of first partial products of a multiplicand that do not reflect implicit carry operations. The compressor sums the first partial products via a configuration of carry save adders that generate sum bits and carry bits, where generation of the carry bits is disabled during execution of the carryless multiplication. The left shifter shifts bits of one or more outputs of the compressor. The exclusive-OR logic is coupled to the compressor and the left shifter, and is configured to execute an exclusive-OR function on the outputs to yield a carryless multiplication result.

Abstract: A microprocessor includes a first-level cache memory, a second-level cache memory, and a data prefetcher that detects a predominant direction and pattern of recent memory accesses presented to the second-level cache memory and prefetches cache lines into the second-level cache memory based on the predominant direction and pattern. The data prefetcher also receives from the first-level cache memory an address of a memory access received by the first-level cache memory, wherein the address implicates a cache line. The data prefetcher also determines one or more cache lines indicated by the pattern beyond the implicated cache line in the predominant direction. The data prefetcher also causes the one or more cache lines to be prefetched into the first-level cache memory.

Abstract: A microprocessor is provided with a reset logic flag and corresponding reset microcode that selectively enables the reset microcode to set up and enable debug logic before the microprocessor subsequently fetches and executes user instructions. When the reset logic flag is set to a debug mode, the reset microcode configures and enables the microprocessor's debug logic before the microprocessor subsequently fetches and executes user instructions. When the reset logic flag is set to a normal mode, the reset microcode refrains from configuring and enabling the microprocessor's debug logic. The reset logic flag is indicated by an alterable fuse or a debugger-programmable scan register. Debug configuration initialization values are also provided by several alternative structures, including the reset microcode itself, alterable fuses, and debugger-programmable scan registers. Corresponding methods are also provided for configuring the debug logic of a microprocessor.

Abstract: A microprocessor includes a storage element that stores decryption key data and a fetch unit that fetches and decrypts program instructions using a value of the decryption key data stored in the storage element. The fetch unit fetches an instance of a branch and switch key instruction and decrypts it using a first value of the decryption key data stored in the storage element. If the branch is taken, the microprocessor loads the storage element with a second value of the decryption key data for subsequent use by the fetch unit to decrypt an instruction fetched at a target address specified by the branch and switch key instruction. If the branch is not taken, the microprocessor retains the first value of the decryption key data in the storage element for subsequent use by the fetch unit to decrypt an instruction sequentially following the branch and switch key instruction.

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: 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 microprocessor includes a memory that stores an exception handler to handle an exception condition. The exception handler is a non-user program private to the microprocessor and includes a conditional branch instruction. A first fetch unit fetches instructions of a user program that includes a user program instruction that causes the exception condition. An execution unit executes the user program instructions fetched by the first fetch unit and executes instructions of the exception handler. The execution unit also saves a state in response to detecting the exception condition caused by the user program instruction. A second fetch unit fetches the exception handler instructions from the memory and resolves the conditional branch instruction based on the saved state without sending the conditional branch instruction to the execution unit to resolve the conditional branch instruction.

Abstract: An apparatus is provided for performing carryless multiplication. The apparatus has an opcode dectector and a carryless preformat unit. The opcode dectector is configured to receive a carryless multiplication instruction, and is configured to assert a carryless signal responsive to receipt of the carryless multiplication instruction. The carryless preformat unit is configured to partition the first operand into parts responsive to assertion of the carryless signal, where the parts are configured such that a Booth encoder selects first partial products corresponding to a second operand and is precluded from selection of second partial products corresponding to the second operand, and where the second partial products are results of implicit carry operations. The first partial products are exclusive-ORed together to yield a carryless multiplication result.

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 microprocessor includes a translation lookaside buffer, a request to load a page table entry into the microprocessor generated in response to a miss of a virtual address in the translation lookaside buffer, and a prefetch unit. The prefetch unit receives a physical address of a first cache line that includes the requested page table entry and responsively generates a request to prefetch into the microprocessor a second cache line that is the next physically sequential cache line to the first cache line.

Abstract: A microprocessor instruction translator translates a conditional load instruction into at least two microinstructions. An out-of-order execution pipeline executes the microinstructions. To execute a first microinstruction, an execution unit receives source operands from the source registers of a register file and responsively generates a first result using the source operands. To execute a second the microinstruction, an execution unit receives a previous value of the destination register and the first result and responsively reads data from a memory location specified by the first result and provides a second result that is the data if a condition is satisfied and that is the previous destination register value if not. The previous value of the destination register comprises a result produced by execution of a microinstruction that is the most recent in-order previous writer of the destination register with respect to the second microinstruction.

Abstract: A circuit substrate includes a base layer, a first patterned conductive layer, a dielectric layer, a conductive block and a second patterned conductive layer. The first patterned conductive layer is disposed on the base layer and has a first pad. The dielectric layer is disposed on the base layer and covers the first patterned conductive layer, wherein the dielectric layer has an opening and the first pad is exposed by the opening. The conductive block is disposed in the opening and covers the first pad. The second patterned conductive layer is disposed on a surface of the dielectric layer and has a second pad, wherein the second pad and the conductive block are integrally formed.

Abstract: An apparatus for predicting leading sign digits in a negative difference includes a comparator that determines a larger of two numbers that differ in magnitude by not more than one digit position. The larger of the two numbers is designated as the subtrahend and the smaller as the minuend. Wires and logic align the subtrahend relative to the minuend by the not more than one digit position and invert the aligned subtrahend. A plurality of NAND gates performs a Boolean NAND function of corresponding digits of the minuend and the aligned inverted subtrahend to produce a prediction string of bits. A zero value is assigned to the most significant bit of the prediction string. A string of leading zeros of the prediction string predicts a corresponding string of leading sign digits of a negative difference of the minuend and aligned subtrahend.

Abstract: A microprocessor includes two or more processing cores each configured to determine, at each of succeeding instances in time, an amount of energy consumed by the microprocessor during a period preceding the instance in time. The period is predetermined. Each core also operates at a frequency above a predetermined frequency in response to determining the amount of energy consumed is less than a predetermined amount of energy. All of the cores may operate above the predetermined frequency simultaneously until one of the cores determines the microprocessor has consumed more than the predetermined amount of energy during the period preceding the instance in time. The predetermined frequency may be: a frequency at which all the cores can operate over the predetermined period without the microprocessor consuming more than the predetermined amount of energy, or alternatively the maximum frequency at which system software may request the cores to operate.

Abstract: An apparatus providing for a secure execution environment. The apparatus includes a microprocessor and a secure non-volatile memory. The microprocessor is configured to execute non-secure application programs and a secure application program, where the non-secure application programs are accessed from a system memory via a system bus. The secure non-volatile memory is coupled to the microprocessor via a private bus. The secure non-volatile memory is configured to store the secure application program, where transactions over the private bus between the microprocessor and the secure non-volatile memory are isolated from the system bus and corresponding system bus resources within the microprocessor.

Abstract: An apparatus in a microprocessor that has an instruction set architecture in which instructions may include a length-modifying prefix used to select an address/operand size other than a default address/operand size, wherein the apparatus marks the start byte and the end byte of each instruction in a stream of instruction bytes. Decode logic decodes each instruction byte of a predetermined number of instruction bytes to determine whether the instruction byte specifies a length-modifying prefix and generates a start mark and an end mark for each of the instruction bytes based on an address/operand size. Operand/address size logic provides the default operand/address size to the decode logic to use to generate the start and end marks during a first clock cycle during which the decode logic decodes the predetermined number of instruction bytes.

Abstract: A hardware integer saturation detector that detects both whether packing a 32-bit integer value causes saturation and whether packing each of first and second 16-bit integer values causes saturation, where the first 16-bit integer value is the upper 16 bits of the 32-bit integer value and the second 16-bit integer value is the lower 16 bits of the 32-bit integer value. The detector includes hardware signal logic, configured to generate four signals with information about the integer values. The hardware integer detector also includes saturation logic, configured to gate the four signals to generate a saturation signal. Each bit of the saturation signal indicates whether packing the 32-bit integer value or whether packing one of the first and second 16-bit integer values will cause saturation respectively.

Abstract: A computer system and a power-management method thereof are provided. The computer system has an image-reading mode, a first power-management mode and a second power-management mode, and the computer system operating in the second power-management mode consumes less power than it consumes in the first power-management mode. The computer system comprises a first portion comprising a graphics processing unit, a memory space and a display; and a second portion comprising a storage storing an image data. When the computer system operates in the image-reading mode, the image data has been transferred to the memory space from the storage, the second portion enters to the second power-management mode from the first power-management mode, and the first portion keeps in the first power-management mode, so that the graphics processing unit can display an image by the display according to the image data stored in the memory space.

Abstract: A method for reconstructing geometry mapping of a rasterized area is provided. The method includes: finding a testing pixel within the rasterized area; finding an occluding point corresponding to the testing pixel in a geometry shadow map of the rasterized area; determining weight values of the occluding point according to the (x, y) coordinate values of the testing pixel and vertices of a triangle occluding the testing pixel in the rasterized area; determining depth value of the occluding point according to the weight value and z coordinate of the vertices of the occluding triangle; and comparing the depth value of the occluding point with the depth value of the testing pixel so as to determine whether the testing pixel is drawn in light or in shadow.