Abstract: A computing device having partitions, and a method of communicating between partitions, are disclosed wherein at least one partition comprises: at least one register substantially always accessible to other partitions and capable of defining an address area; at least one address area that may be accessible to other partitions and is capable of being defined by the at least one register; and address areas other than the at least one accessible address area that are not accessible to other partitions. A method of processing interrupts comprising receiving an interrupt, assessing the origin of the interrupt, accepting, rejecting, or further assessing the interrupt, depending on its origin, when further assessing the interrupt, accepting or rejecting the interrupt depending on its contents, and forwarding accepted interrupts but not rejected interrupts to a target processor, and a device carrying out that method are also disclosed.

Abstract: A method of operating a central cache controller (“CCC”) in a first cell of a multiprocessor system comprising multiple cells each including globally shared memory (“GSM”), wherein the first cell is disposed in a first partition and the CCC is connected to a plurality of CPUs of the first cell. In one embodiment, the method comprises, responsive to a new transaction request from one of the CPUs, logging the transaction in a transaction table; determining whether an identity marker in a timeout map corresponding to a cell to which the transaction was issued is set; and, responsive to the corresponding identity marker in the timeout map being set, immediately returning a special error to the one of the CPUs that requested the transaction.

Abstract: Transactions are received through at least two input channels, each transaction comprising one or more data packets. The data packets are placed in a single data queue. When a first transaction received through one input channel comprises more than one data packet, a data packet of a second transaction received through another input channel is permitted to be placed in the single data queue between data packets of the first transaction. A block of space in a data output queue is assigned to each transaction. Each data packet is placed in the block assigned to its transaction.

Abstract: A circuit for tracking the minimum and maximum duration of an event of interest is described. The circuit is connected to a counter for counting a number of clock cycles that the event of interest is active and comprises logic for detecting deactivation of the event of interest and generating a duration end signal; logic responsive to the duration end signal for comparing a count value with a shadow value; and logic for updating the shadow value based on results of the comparing.

Abstract: A system for validating data collected in a first clock domain. A performance counter is disposed in a second clock domain to perform performance computations relative to the data. Validation circuitry is in communication with the data in order to provide to the performance counter a validation signal indicative of the validity of the data.

Abstract: A system and method for effectuating the transfer of data blocks including a header block across a clock boundary between a first clock domain and a second clock domain. In one embodiment, a first circuit portion provides the data blocks including the header block to a second circuit portion. Control logic associated with the second circuit portion is operable to process the header block and generate in response to the header block a hint signal which is transferred via a synchronizer at least one data cycle prior to the transfer of the data blocks to a third circuit portion disposed in the second clock domain. A control block associated with the third circuit portion operates responsive to the hint signal to generate data transfer control signals for controlling the third circuit portion in order to control output of the data blocks in a particular ordered grouping.

Abstract: A system and method for effectuating the transfer of data blocks having intervals across a clock boundary between a first clock domain and a second clock domain. A first circuit portion provides the data blocks to a second circuit portion. A synchronizer controller disposed between the first and second clock domains provides at least one dead cycle control signal to the second circuit portion, which is indicative of the location of at least one dead cycle between the first and second clock signals. Control logic associated with the second circuit portion generates data transfer control signals responsive to the at least one dead cycle control signal in order to control the second circuit portion so that the data blocks may be transmitted as contiguous data blocks relative to the at least one dead cycle.

Abstract: An increment/decrement circuit for use with a general purpose performance counter (“GPPC”) connected to a bus carrying debug data. In one embodiment, the increment/decrement circuit includes a delay circuit block operable to receive and align the debug data. First and second mask circuits are connected in parallel to the delay circuit block in order to select and assert portions of the aligned debug data for incrementing and decrementing, respectively. An accumulation circuit is connected to the first mask circuit and the second mask circuit for generating an accumulated value based on the outputs of the mask circuits.

Abstract: A match circuit connected to a bus carrying data is described. In one embodiment, the match circuit includes logic for activating a decoded_match signal, the logic for activating a decoded match signal comprising logic for decoding a sum field comprising a selected portion of the data into a decoded_sum signal, wherein an active bit of the decoded_sum field corresponds to a value of the sum field; and logic for comparing the decoded_sum signal with a mask signal and outputting a binary bit comprising a decoded_match signal indicative of whether the decoded_sum signal and the mask signal match.

Abstract: Delivering data from a data input to a data output within a system includes selecting a system performance parameter to be optimized, receiving at the data input a sequence of discrete data words, determining an optimum mode of delivery of the data words to the data output so as to optimize the selected performance parameter, and delivering the data words from the data input to the data output in the determined optimum mode. The optimum mode of delivery may include at least one of an optimum time and sequence of delivery of the data words.

Abstract: A controller arrangement and method for effectuating data transfer between a first clock domain and a second clock domain. In one embodiment, inversion circuitry inverts a first clock signal associated with the first clock domain into an inverted first clock signal that is used in effectuating a SYNC pulse during coincident edges of the inverted first clock signal and a second clock signal associated with the second clock domain. Clock synchronizer controller circuitry operates responsive to sampled sync pulses based on the SYNC pulse to generate domain synchronizer control signals for effectuating data transfer between the first and second clock domains.

Abstract: In one embodiment, the invention is directed to a zeroing circuit for a general purpose performance counter (“GPPC”) connected to a bus carrying debug data. The zeroing circuit comprises logic for zeroing out a specified number of most significant bits (“MSBs”) of a selected portion of the debug data based on a mask generated by a mask generator block. A selection control signal provided to the mask generator block is operable to be decoded to a particular mask.

Abstract: In one embodiment, the invention is directed to a general purpose performance counter (“GPPC”) connected to a bus carrying debug data. The GPPC includes an AND/OR circuit connected to receive the debug data; a counter circuit connected to receive from the AND/OR circuit an increment signal that, when activated, causes the counter circuit to increment a count; and a compare circuit for activating a match/threshold signal to the AND/OR circuit responsive to a selected block of the debug data having a first relationship to a compare value, wherein the AND/OR circuit activates the increment signal responsive to a selected combination of bits of an events signal being set.

Abstract: Disclosed are systems and methods for logging errors comprising at least one register for storing header packet information, a controller operable to determine if a received packet of one or more packets forming an information communication comprises a header packet and to store the header packet in said at least one register, and error logging circuitry coupled to the register operable to create an error log entry using header information retrieved from the register when an error is detected with respect to any of the one or more packets of the information communication.

Abstract: A coverage circuit for use with a general purpose performance counter (“GPPC”) connected to a bus for capturing test coverage information encoded as N one-hot signals indicative of coverage in a logic design. An OR logic block is included for bit-wise ORing the N one-hot signals with a N-bit mask value stored in a register block so that an N-bit output may be generated by the OR logic block depending on the logic transitions of the one-hot signals. A Multiplexer (MUX) block is provided for selecting the N-bit output from the OR logic block under control of at least one control signal, wherein the N-bit output is operable to be stored into the register block when selected by the MUX block.

Abstract: In one embodiment, the invention is directed to a data selection circuit for a general purpose performance counter (“GPPC”) connected to a bus carrying debug data. The data selection circuit is connected to receive the debug data and comprises logic for receiving the debug data as a plurality of N-bit portions of block-aligned data and outputting a designated one of the N-bit portions; and circuitry for providing to the receiving logic a control signal for designating one of the N-bit portions.

Abstract: A programmable sync pulse generator and sync pulse generation method are operable in a clock synchronizer to effectuate data transfer between first circuitry disposed in a first clock domain and second circuitry disposed in a second clock domain. The first clock domain is operable with a first clock signal and the second clock domain is operable with a second clock signal. A phase detection circuitry is operable to sample the first clock signal with the second clock signal to determine coincident edges of the first and second clock signals. Validation circuitry is operable to validate the coincident edges based upon skew tolerance between the first and second clock signals and to generate a valid edge signal responsive thereto. Sync generation circuitry, responsive to the valid edge signal, is operable to generate synchronization pulses in the first clock domain and synchronization pulses in the second clock domain.

Abstract: Disclosed are systems and methods for controlling transaction draining for error recovery comprising asserting a control signal to prevent system resources associated with a particular error from issuing new requests, dropping transactions tracked by an out-of-order queue, and issuing transactions not tracked by the out-of-order queue.

Abstract: A match circuit connected to a bus carrying data is described. In one embodiment, the match circuit comprises logic for activating a match_mm signal when a selected N-bit portion of the data matches an N-bit threshold for all bits selected by an N-bit match mask (“mmask”) and logic for activating a match_OR signal when at least one of one or more designated bits of the selected N-bit portion of the data is a logic 1 or if there are no designated bits.

Abstract: A drift-tolerant sync generation circuit and sync generation method for a sync pulse generator operable in a clock synchronizer that effectuates data transfer between first circuitry disposed in a first clock domain and second circuitry disposed in a second clock domain. The first clock domain is operable with a first clock signal and the second clock domain is operable with a second clock signal. A sync circuit portion, responsive to a valid edge signal indicative of coincident edges between the first and second clock signals, is operable to generate based upon the ratio a start sync signal substantially centered around the coincident edges. A first sync generator, responsive to the start sync signal, is operable to generate synchronization pulses in the first clock domain. A second sync generator, responsive to the start sync signal, is operable to generate synchronization pulses in the second clock domain.