Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Gregory L Ranson

Gregg Bernard Lesartre

Russell C Brockmann

John William Bockhaus

Douglas Benson Hunt

Patrick Knebel

Steven T Mangelsdorf

Paul L Perez

Robert E Naas

Charles Corey Pie

Jonathan P Lotz

Bruce A Doyle

A method for analyzing integrated circuits (IC's) has steps of dividing the circuit into a plurality of individual blocks that are linked together. Each block is comprised of a plurality of latches and paths connecting the latches. The blocks are compressed by removing all detail not required for performing global transparency timing modeling.

Integrated circuit analysis method and program product

Systems, methodologies, media and other embodiments associated with peak detectors are described. One exemplary system embodiment includes a voltage peak detector comprising a first detector logic configured to detect a peak voltage of an input signal. The first detector logic has a circuit behavior that produces a leakage current that may alter the peak voltage. The system can also include a second detector logic configured to replicate the circuit behavior of the first detector logic including being configured to produce a replica leakage current that is equivalent to the leakage current. The second detector logic can be operably connected to the first detector logic to cause the replica leakage current to negate the leakage current.

Peak detector systems and methods with leakage compensation

Two or more cross-triggering CPUs for enhancing test operations in a multi-CPU computer system. Method for using same. A first CPU has a first trigger input, a first trigger output and first internal test-facilitating circuitry operable to assert the first trigger output when a first event occurs within the first CPU, and also operable to take a first test-facilitating action response to an assertion of the first trigger input. A second CPU has a second trigger input, a second trigger output and second internal test-facilitating circuitry operable in the same way. The first trigger output is coupled to the second trigger input, and the second trigger output is coupled to the first trigger input. (The arrangement may be extended to include any number of CPUs.) The trigger input and trigger output in each CPU may both be coupled to a bidirectional chip pad in the CPU, and the bidirectional chip pads of each CPU coupled together. The internal test-facilitating circuitry may include a programmable state machine configured to accomplish the test-facilitating action responsive to the trigger input, and to generate the trigger output responsive to the detection of events occurring within the CPU. State machine output devices may include: trap circuitry for causing the CPU to execute a trap routine; clock hold circuitry for causing the system clock within the CPU to hold; sample-on-the-fly circuitry for latching the state of a plurality of nodes within the CPU; or counter circuitry for counting events.

Cross-triggering CPUs for enhanced test operations in a multi-CPU

Circuitry for providing external access to signals that are internal to an integrated circuit chip package. A plurality of N:1 multiplexers are physically distributed throughout the integrated circuit die. Each of the multiplexers has its N inputs coupled to a nearby set of N nodes within the integrated circuit, and each of the multiplexers is coupled to a source of select information operable to select one node from the set of N nodes for external access. Each of the multiplexers has its output coupled to an externally-accessible chip pad. The integrated circuit is a microprocessor, and the source of select information may include a storage element. If so, additional circuitry is provided for writing data from a register of the microprocessor to the storage element using one or more microprocessor instructions. Each multiplexer may be coupled to a different source of select information, or all multiplexers may be coupled to the same select information. Moreover, a fixed set of interconnect traces may be provided to couple a fixed set of nodes to an additional set of externally-accessible chip pads. One or more M:1 multiplexers may also be provided, having their M inputs coupled to M different outputs of the N:1 multiplexers. Each of the M:1 multiplexers may be coupled to a second source of select information. Preferably, the outputs of the M:1 multiplexers will be coupled to a circuitry for facilitating debug and performance monitoring of the integrated circuit.

Circuitry for providing external access to signals that are internal to

Method for detecting when first and second signal patterns have occurred on a split-transaction bus having transaction identifying indicia: Signal patterns occurring on the bus are compared with a first stored signal pattern. If a match is detected, the transaction identifying indicia that were associated on the bus with the first signal pattern are stored, and a first detection signal is asserted and held asserted. Signal patterns on the bus are then compared with a second stored signal pattern, and transaction identifying indicia occurring on the bus are compared with the indicia previously stored. A match signal is asserted when the first detection signal is asserted and, simultaneously, matches are detected for both of the second signal pattern comparison and the transaction identifying indicia comparison. Circuitry for implementing the method: First comparison circuitry asserts a first detection signal when a first signal pattern is detected on the bus. First storage circuitry stores a record of the first detection signal having been asserted. Second storage circuitry stores the transaction identifying indicia present on the bus when the first signal pattern is detected. Second comparison circuitry compares the signal patterns on the bus with a stored signal pattern, and third comparison circuitry compares the transaction identifying indicia present on the bus with the indicia stored in the second storage circuitry. When the second and third comparison circuitries simultaneously indicate matches and the first storage circuitry indicates that the first signal pattern was previously detected, output generation circuitry asserts a match signal.

Circuitry and method for detecting signal patterns on a bus using

Method of processing information in a microprocessor. At a first time during the life cycle of an instruction, a first set of microprocessor self-monitoring information is generated. The first set of mnicroprocessor self-monitoring information is stored, information necessary to execute the instruction is stored, and the two are associated. At a second time during the life cycle of the instruction, a second set of microprocessor self-monitoring information may be generated. This is also stored and is associated with the information necessary to execute the instruction. If the instruction retires, the first and second information may be retrieved for use in microprocessor testing. The information may also be used as soon as it is generated, for example by communicating the information itself or indicators derived from it to a state machine configured to facilitate microprocessor testing. The invention may also include a method of processing information in a microprocessor to facilitate microprocessor testing operations, wherein system bus monitoring information is generated whenever system bus accesses occur. This information, or indicators derived from it, is communicated to a microprocessor testing state machine on-chip with the microprocessor. In yet other embodiments, the invention may include the steps of: generating microprocessor self-monitoring information at various times during the life cycle of an instruction; utilizing the microprocessor self-monitoring information both when it becomes available as well as later, after retirement of the associated instruction; generating system bus monitoring information whenever system bus accesses occur; and utilizing the system bus monitoring information when it becomes available.

Method for processing information in a microprocessor to facilitate

Method for efficiently and flexibly comparing a group of multi-bit binary fields with a multi-bit expected pattern to generate a set of final match results, one final match result for each binary field in the group. Sets of of bit-wise comparator results are generated, one set for each binary field, by comparing each binary field with the expected pattern. Then, sets of bit-wise mask results are generated for each binary field by bit-wise masking each set of bit-wise comparator results with a mask pattern. Then, a set of preliminary match results is generated. Each preliminary match result is equal to the logical AND of all bits making up the bit-wise mask result set for the corresponding binary field. Then, a set of secondary match results is generated by negating all of the preliminary match results if a negate indicator is asserted. Finally, a set of final match results is generated, one final match result for each binary field, by individually gating all of the secondary match results with a separate enable indicator for each binary field. The invention includes an M.times.N comparator matrix for accomplishing the just-described method. The invention also includes circuitry for comparing N binary fields with an expected pattern to generate N comparison results.

Apparatus and method for comparing a group of binary fields with an

In one embodiment, the invention includes a method of tracking events in a microprocessor that can retire more than one instruction during a clock cycle. A set of match results is generated during each clock cycle, one match result for each retiring instruction. Each of the match results indicates whether the corresponding retiring instruction matched a criterion. Then, the total number of retiring instruction that matched the criterion is determined by adding the asserted match results to generate a sum. A counter is incremented by the sum. In another embodiment, the invention includes circuitry for implementing the just-described method. Match generator circuitry is provided for generating a set of match results during each clock cycle, one match result for each retiring instruction. The outputs of the match generator circuitry are supplied to adder circuitry. The adder circuitry is operable to determine the number of said match results that are asserted and to represent the number as a sum via a set of adder circuitry outputs. A counter having a set of adder circuitry inputs is coupled to adder circuitry outputs. The counter is operable to increment its count by the sum represented by the adder circuitry outputs. In further embodiments, a multiplexer is interposed between the adder circuitry and the counter. The multiplexer has a first set of inputs coupled to the adder circuitry outputs, and a second set of inputs coupled to a source of the value '1.' The multiplexer is operable to present either the first or second inputs on its outputs responsive to a select signal. The multiplexer has its outputs coupled to the increment inputs of the counter.

Apparatus and method for tracking events in a microprocessor that can

Circuitry for detecting signal patterns on a multi-bit bus. First comparison circuitry monitors a first portion of the bus comparing it with a first expected signal pattern, generating a first comparison output. Second comparison circuitry monitors a second portion of the bus comparing it with a second expected signal pattern, generating a second comparison output. Both comparison outputs are applied to an AND gate and a first OR gate. One data input of a multiplexer is coupled to the output of the first OR gate. Another data input is coupled to the output of the AND gate. Another data input is coupled to the first comparison output, and another data input is coupled to the second comparison output. One input of a second OR gate may be coupled to the multiplexer output, and another input coupled to a disable indicator, allowing the multiplexer output to be overridden. The first and second comparison outputs may be generated by bit-wise comparing first and second portions of the bus with first and second expected signal patterns. The logical AND of the respective comparison results may be treated as the first and second comparison outputs, or they may be treated as first and second intermediate bits. These first and second intermediate bits may be ORed with first and second mask bits, and the results may be treated as the first and second comparison outputs. The outputs of the two OR operations may also be EXCLUSIVE ORed with first and second negate bits, respectively.

Flexible circuitry and method for detecting signal patterns on a bus

Method for decoding inputs in a programmable state machine, including the following steps: bit-wise comparing state machine inputs with select information to produce bit-wise comparison results; determining the logical AND of the bit-wise comparison results; and determining the logical EXCLUSIVE OR of a negate indicator and the logical AND. In a further embodiment, a step of bit-wise ORing the comparison results with mask information is performed before the logical AND step. Circuitry for implementing the method: A bit-wise comparator has two sets of inputs. Its first set of inputs is coupled to state machine input signals. Its second set of inputs is coupled to select information. It is operable to produce bit-wise comparator outputs that indicate the results of bit-wise comparing the state machine input signals with the select information. AND circuitry has an AND circuitry output to indicate the logical AND of the comparator outputs. An EXCLUSIVE OR gate has its first input coupled to the AND circuitry output and has its second input coupled to a negate indicator. The output of the EXCLUSIVE OR gate constitutes the output of the inventive input comparison circuitry. In further embodiments, bit-wise OR circuitry may be interposed between the comparator and the AND circuitry. Such bit-wise OR circuitry may be used for masking by coupling its first set of inputs to the comparator outputs and coupling its second set of inputs to mask information. In the latter embodiment, the bit-wise results of the OR circuitry are ANDed by the AND circuitry.

Input comparison circuitry and method for a programmable state machine

User-configurable diagnostic hardware contained on-chip with a microprocessor for the purpose of debugging and monitoring the performance of the microprocessor. Method for using the same. A programmable state machine is coupled to on-chip and off-chip input sources. The state machine may be programmed to look for signal patterns presented by the input sources, and to respond to the occurrence of a defined pattern (or sequence of defined patterns) by driving certain control information onto a state machine output bus. On-chip devices coupled to the output bus take user-definable actions as dictated by the bus. The input sources include user-configurable comparators located within the functional blocks of the microprocessor. The comparators are coupled to storage elements within the microprocessor, and are configured to monitor nodes to determine whether the state of the nodes matches the data contained in the storage elements. By changing data in the storage elements, the programmer may change the information against which the state of the nodes is compared and also the method by which the comparison is made. The output devices include counters. Counter outputs may be used as state machine inputs, so one event may be defined as a function of a different event having occurred a certain number of times. The output devices also include circuitry for generating internal and external triggers. User-configurable multiplexer circuitry may be used to route user-selectable signals from within the microprocessor to the chip's output pads, and to select various internal signals to be used as state machine inputs.

System and method for on-chip debug support and performance monitoring

A method and apparatus is disclosed for reading data from and writing data to remote registers that are dispersed throughout an integrated circuit chip. Regardless of the size or number of remote registers involved, the operation is accomplished using only two interconnect lines, plus a clock. Each remote register is associated with a unique address. During a write operation, a microprocessor loads the write data into a staging register, loads the destination address into a header generation register along with a read/write control bit, and loads a count value into a clock. Thereafter, the apparatus of the invention proceeds automatically, as the clock counts down, to shift the data onto a serial data line following a header. Each of the remote registers in the system are arranged serially, and each monitors the header information, comparing the address contained in the header with its own address. In the event of a match, the remote register selected is enabled to shift data serially into itself from the serial data line. During a read operation, the selected remote register shifts its data out onto the serial data line. The read data is ultimately shifted back into the staging register.

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Fort Collins, CO, United States of America

Gregory L Ranson