WO2003038613A1 - Emulating components and system including distributed emulation methods - Google Patents

Emulating components and system including distributed emulation methods Download PDF

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Publication number
WO2003038613A1
WO2003038613A1 PCT/US2002/034690 US0234690W WO03038613A1 WO 2003038613 A1 WO2003038613 A1 WO 2003038613A1 US 0234690 W US0234690 W US 0234690W WO 03038613 A1 WO03038613 A1 WO 03038613A1
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WIPO (PCT)
Prior art keywords
emulation
logic
data processing
board
resources
Prior art date
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PCT/US2002/034690
Other languages
French (fr)
Inventor
Frederic Reblewski
Original Assignee
Mentor Graphics Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/003,951 external-priority patent/US7035787B2/en
Priority claimed from US10/003,184 external-priority patent/US7130788B2/en
Application filed by Mentor Graphics Corporation filed Critical Mentor Graphics Corporation
Publication of WO2003038613A1 publication Critical patent/WO2003038613A1/en

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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00Computer-aided design [CAD]
    • G06F30/30Circuit design
    • G06F30/32Circuit design at the digital level
    • G06F30/33Design verification, e.g. functional simulation or model checking
    • G06F30/3308Design verification, e.g. functional simulation or model checking using simulation
    • G06F30/331Design verification, e.g. functional simulation or model checking using simulation with hardware acceleration, e.g. by using field programmable gate array [FPGA] or emulation

Definitions

  • the present invention relates to the field of emulation. More specifically, the present invention relates to the components, such as integrated circuits and logic boards, employed to form emulation systems, and various distributed emulation methodologies practiced thereon.
  • the first generation of prior art emulation systems were typically formed using general purpose FPGAs without integrated debugging facilities.
  • the circuit design would be "realized” by compiling a formal description of the circuit design, partitioning the circuit design into subsets, mapping the various subsets to the logic elements (LEs) of the FPGAs of various logic boards of the emulation system, and then configuring and interconnecting the LEs.
  • the partitioning and mapping operations would be typically performed on workstations that are part of or complementary to the emulation systems, while the configuration information would be correspondingly downloaded onto the logic boards hosting the FPGAs, and then onto the FPGAs.
  • test stimuli are either generated on the workstation or on a service board of the emulation system under the control of the workstation, and then transfer to the various logic boards for input into the emulation ICs for application to the various netlists of the IC design being emulated.
  • State data of various circuit elements as well as signal states of interest of the IC design being emulated, would be correspondingly read out of the applicable FPGAs, and then transfer off the logic boards, for analysis on the workstation.
  • FPGAs field-programmable gate arrays
  • emulation ICs typically would include substantial amount of on-chip reconfigurable logic elements, inteconnects, memory as well as debugging resources. As the advances continue, more and more of these resources are packed into each emulation IC. As a result, more and more control signals have to be transferred onto each logic board (for transfer into the emulation ICs) to configure the emulation ICs of the logic board.
  • data processing resources are distributively provided to an emulation system to locally and correspondingly generate configuration signals to configure selected ones of reconfigurable logic and interconnect resources of corresponding collections of reconfigurable logic and interconnect resources, to emulate corresponding partitions of an IC design.
  • the distributed data processing resources further locally and correspondingly determine inteconnect routing within the selected ones of reconfigurable logic resources of the corresponding collections of reconfigurable logic resources.
  • data processing resources are distributively provided to an emulation system to locally and correspondingly generate testing stimuli, and applying the generated testing stimuli to partitions of an IC design to be emulated.
  • the distributed data processing resources further locally and correspondingly retrieve state data of emulation state circuit elements, analyze the retrieved state data for one or more events, and report the one or more events upon their detection.
  • data processing resources are distributively provided in an emulation system to locally and correspondingly pre-process captured signal states of signals of partitions of an IC design being emulated to facilitate reporting on a plurality of the signal states, in response to a request for the signal states.
  • the local and corresponding pre-processing includes local and corresponding re-creation of a plurality of unobservable ones of the requested signal states, based on a number of locally observed ones of the signal states, in accordance with a number of provied mapping functions.
  • the distributed data processing resources also locally and correspondingly compress the signals of interest, and report the signals in a compressed form to reduce the data transmission bandwidth requirement between the logic boards and the control workstation of the emulation system.
  • the distributed data processing resources are disposed on logic boards having emulation ICs that include the reconfigurable logic and interconnect resources. In other embodiments, at least some of the distributed data processing resources are disposed on the emulation ICs.
  • the board and IC disposed distribtued data processing resources cooperatively perform the earlier mentioned distributed emulation methods.
  • the present invention also contemplates the consitution of an emulation system using the aforementioned emulation ICs and logic boards.
  • FIG. 1 illustrates the major functional blocks of a logic board incorporated with the teachings of the present invention, in accordance with one embodiment
  • Figure 2a-2b illustrate a hosted emulation IC of Fig. 1 in further details, including the on-chip debugging resources of the emulation IC in further details, in accordance with one embodiment
  • FIG. 3 illustrates the on-board data processing resources of Fig. 1 in further details, in accordance with one embodiment
  • Figure 4 illustrates an overview of the software modules provided to the data processing resources of Fig. 3 in further details, in accordance with one embodiment
  • Figure 5 illustrates an example packet suitable for use to communicate with the data processing resources of Fig. 1 , in accordance with one embodiment
  • Figure 6 illustrates an emulation system of the present invention, formed with the emulation logic board of the present invention, in accordance with one embodiment
  • Figure 7 illustrates the operation flow of a method of the present invention for distributively and correspondingly routing the interconnects for circuit elements of the netlists of a partition of an IC design, and configuring the reconfigurable resources of the emulation system, in accordance with one embodiment
  • Figure 8 illustrates the operation flow of a method of the present invention for distributively and correspondingly pre-processing trace data of interest of an IC design being emulated, in accordance with one embodiment
  • Figure 9 illustrates the operation flow of a method of the present invention for distributively and correspondingly generating and applying testing stimuli, as well as monitoring for occurrences of selected events, in accordance with one embodiment
  • Figure 10 illustrates a hosted emulation IC of Fig. 1 in further details, in accordance with an alternate embodiment.
  • logic board 100 of the present invention includes on-board data processing resources 102, on-board emulation ICs 104, on-board reconfigurable interconnects 106, on-board bus 108, and on-board trace memory 110 coupled to each other as shown (i.e. through on-board bus 108). Additionally, on-board emulation ICs 104 are also directly coupled to on-board trace memory 110. Logic board 100 further includes a number of I/O pins (not explicitly illustrated).
  • a novel emulation system may be formed using multiple ones of logic board 100 and control resources, wherein data processing resources 102 of the various logic boards 100 may be employed to locally and correspondingly (i.e. distributively) perform a number of emulation functions on behalf of and at the direction of the control resources. As a result, the operation efficiency of the novel emulation system is improved.
  • Emulation ICs 104 in particular, their on-chip reconfigurable logic and interconnect resources, as in prior art "FPGAs", are used to "realize” the netlists of an IC design to be emulated.
  • each emulation IC 104 may advantageously include integrated debugging facilities, such as those included with enhanced "FPGAs” described in USP 5,777,489, and co-pending U.S. Patent Application number 08/542,838, to be described more fully below.
  • Reconfigurable interconnects 106 facilitate coupling of the emulation resources of the various emulation ICs 104 of the different logic boards 100 employed to form an emulation system.
  • On-board bus 108 and trace memory 110 perform their conventional functions of facilitating on-board communication/data transfers, and collection of signal states of the various emulation signals of the assigned partition of the IC design being emulated.
  • the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local determination (at the individual board level) of the routing to interconnect the reconfigurable logic resources of the hosted emulation ICs 104 to be used to emulate the circuit elements of the netlists of the partition of an IC design "assigned" to logic board 100 (i.e. distributive routing of an IC design), as well as local generation (at the board level) of configuration signals to configure the emulation resources of the on-board emulation ICs 104 and other on-board emulation resources, such as reconfigurable interconnects 106 (i.e. distributive configuration of emulation resources).
  • Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to routing and configuration requests from the control resources of the emulation system.
  • the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local generation (at the board level) of testing stimuli, and application of the generated testing stimuli to the appropriate "input pins" of the IC design being emulated.
  • the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local determination (at the board level) of the emulation state elements of an IC design being emulated to be monitored, reading of the state data of the emulation state elements to detect occurrence of certain events, and reporting of the occurrence of the events upon their detection.
  • Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to testing and/or monitor requests from the control resources of the emulation system.
  • the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local pre-processing (at the board level) of captured trace data to determine the signal state of one or more signals of interest of the IC design being emulated.
  • Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to trace data requests from the control resources of the emulation system.
  • the novel manners in which these emulation functions are performed provide at least the advantage of reducing the amount of control signals and data needed to be transferred in and out of emulation logic board 100 to configure emulation resources of emulation ICs 104 to emulate and debug an assigned partition of an IC design. Additionally, the present invention also provides the advantage of speeding up debugging, testing, including co- simulation of a hardware-software design, performed using an emulation system constituted with multiple ones of logic boards 100.
  • On-board bus 108, reconfigurable interconnects 106, system bus 108 and trace memory 110, are intended to represent a broad range of these elements known in the art, accordingly will not be further described. At least one embodiment each for emulation ICs 104 and data processing resources 102 are described in turn below.
  • emulation IC 104 includes reconfigurable LEs (RLR) 202, reconfigurable interconnects (RIN) 204, emulation memory (MEM) 206, debugging resources (DBR) 208, context or state elements (CTX) 210, and configuration registers (CR) 212 and 214 coupled to each other as shown.
  • RLR reconfigurable LEs
  • RIN reconfigurable interconnects
  • MEM emulation memory
  • DBR debugging resources
  • CTX context or state elements
  • CR configuration registers
  • reconfigurable LEs 202 are used to "realize” the combinatorial logic of the netlists of the assigned partition of an IC design to be emulated.
  • Context/state elements 210 are used to "realize” state elements of the netliest of the assigned partition of the IC design to be emulated, such as flip-flops, and so forth, whereas emulation memory 206 are used to "realize” storage elements of the netlists of the assigned partition of the IC design to be emulated.
  • Reconfigurable interconnects 204 are used to reconfigurbaly couple LEs 202, memory 206 and so forth.
  • configuration of these elements including determination of the interconnect routing, to emulate the netlists of an assigned partition of an IC design, reading of state data of state elements, including determination of which state elements to read, capturing of signal states, includingre-creation of "unobservable” signals, are locally (i.e. distributively) performed by data processing resources 102 of the host logic board 100, to be described more fully below.
  • FIG. 2b illustrates certain aspects of debugging resources 208 of emulation IC 104 in further details in accordance with one embodiment.
  • debugging resources 208 of an emulation IC 104 include scan memory 224 and reconfigurable interconnect 222 reconfigurably coupling scan memory 224 to the reconfigurable logic resources 202 of emulation IC 104.
  • Scan memory 224 outputs to on-board trace memory 110.
  • Scan memory 224 is designed to operate responsive to a debug clock that is typically faster than the emulation clock. Accordingly, during one emulation clock cycle, scan memory 224 may enable signal states of different signals of the netlists of an assigned partition of an IC design being emulated to be captured.
  • data processing resources 102 include processor 302, dynamic random memory 304, and I/O interface 306, coupled to each other as shown.
  • Processor 302, memory 304 and I/O interface 306 are also coupled to the earlier described logic board bus 108.
  • Memory 304 is used to store a "working" copy of the various software for performing the local (i.e. distributive) routing determination, configuration signals generation, event detection, test stimuli generation, as well as preprocessing of captured signal states, and so forth.
  • the software is downloaded to memory 304 during initialization.
  • the download is preferably staged with the software associated with interconnect routing determination and configuration signal generation being downloaded first, while the software associated with distributed debugging and testing operations download later.
  • logic board 100 may additionally be provided with non-volatile storage, such that a "permanent" copy of a subset or all of the requisite software may be stored.
  • Processor 302 is used to execute the software and effectuate performance of the aforementioned functions, whereas I/O interface 306 facilitates communication between processor 302 and other entities external to logic board 100. Except for the novel use of these elements to effectuate provision of the desired advantages, these elements of data processing resources 102 are otherwise known in the art, accordingly will not be further described.
  • FIG. 4 illustrates an overview of the software modules provided to data processing resources 102 to provide the desire functionalities of the present invention to a logic board, in accordance with one embodiment.
  • software 400 includes control module 402, and functional modules, router 403, configurator 404, trace data processor 406, state data/event detector 408, and test stimuli generator 410.
  • Control module 602 is equipped with control logic to facilitate the overall operation in the delivery of the desired functions, including in particular communication with external entities outside a ( logic board 100, and invocation of appropriate ones of the functional modules.
  • control module 402 communicates with the external entities on a request and response transaction basis, via communication packets.
  • the assigned netlists, as well as the routing, configuration, signal state, state data of state elements, and testing requests are made, acknowledged and responded to using transaction messages sent and received in a series of communication packets.
  • other communication techniques may be used instead.
  • Fig. 5 illustrates an example communication packet, in accordance with one embodiment, is shown.
  • communication packet 500 includes packet header 502, command field 504, parameters associated with the specified commands, or pointers to these parameters 506, and end of packet marking 508.
  • Packet header 502 and EOP 508 facilitate provision of various communication related control information, as common in the art of communication.
  • Command 504 facilitates communication between processor 302 and the external entities on the tasks to be performed, and their results. Parameters or pointers thereto 506 augment the commands or return of results, where appropriate.
  • router 403 is equipped with logic to locally (therefore, correspondingly and distributively) determine the routing for interconnecting the reconfigurable resources of emulation ICs 104 assigned to emulate circuit elements of the netlists of an assigned partition of an IC design to be emulated, responsive to routing requests. Except for the fact that routing of the reconfigurable resources of emulation ICs 104 of a logic board is locally performed on the "assigned" logic board, the tasks of routing, in and of themselves, are otherwise substantially the same when they are centrally performed on a control workstation of an emulation system, and known in the art.
  • Configurator 404 is equipped with logic to locally (therefore, correspondingly and distributively) generate the configuration bits necessary to configure the reconfigurable logic and interconnect resources of emulation ICs 104, and the applicable interconnect resources of the logic board, in accordance with the reconfigurable logic resources and board level inteconnect centrally determined and the reconfigurable interconnect within the emulation ICs 104 locally determined, responsive to configuration requests.
  • generation of the configuration bits is locally performed on the "assigned" logic board, the tasks of generating configuration bits in accordance with a resource allocation, in and of itself, is otherwise substantially the same as the tasks are centrally performed on a control workstation of an emulation system, and also known in the art.
  • Trace data processor 406 is equipped with logic to locally pre-processes the captured signal states of the emulation signals to determine one or more signal states of one or more signals of interest of the netlists of the assigned partition of the IC design being emulated, responsive to trace data requests. Again, except for the fact that the captured signal states of the emulation signals are pre-processed locally, reconfiguration of debugging resources and processing of capture signal states, in and of themselves, are otherwise substantially the same as these tasks are centrally performed on a control workstation of an emulation system, and also known in the art.
  • State data/event monitor 408 is equipped with logic to monitor emulation state elements to detect one or more events. State data/event monitor 408 is further equipped to report the occurrences of the events upon detecting their occurrences.
  • Test vector generator/applicator 410 is equipped with logic to locally (therefore, correspondingly and distributively) generate and apply testing stimuli to the netlists of the assigned partition of the IC design being emulated. Test vector generator/applicator 410 is intended to represent a broad range of testing software known in the art. Similarly, except for the fact that retrieval of state data, event detection, generation and application of test stimuli are locally performed, each of these operations, in and of itself, is substantially the same as the operation is centrally performed at the control workstation.
  • emulation system 600 includes control workstation 602 and emulator 606.
  • Control workstation 602 is equipped with EDA software 604.
  • Emulator 606 includes a number of logic boards 100, each having a number of emulation ICs 104 and on-board data processing resources 102 disposed there on as described earlier.
  • emulator 606 also includes service and I/O boards 608. Boards 100 and 608 are interconnected by inter-board interconnects 610.
  • various boards 100 and 608 are packaged together to form a crate (not shown), and the crates are interconnected together via inter-board interconnect 610.
  • inter-board interconnect 610 The precise numbers of emulation ICs 104 disposed on each board, as well as the precise manner in which the various boards are packaged into crates are unimportant, and application dependent.
  • EDA software 604 is incorporated with the teachings of the present invention, in particular, the corresponding distribution of emulation logic board level routing of the interconnects for netlists of the various partitions of an IC design to be emulated, and configuration of the emulation resources of the emulation ICs of a logic board, to the logic boards themselves. Except for the teachings of the present invention incorporated, EDA software 604 is otherwise intended to represent a broad range of the software typically supplied with an emulation system, including in particular the software for partitioning the netlists of an IC design to be emulated at the system level, and the software for debugging and testing an IC design being emulated, such as model simulators.
  • emulator 606 is also intended to otherwise represent a broad range of emulators known in the art.
  • FIG. 7-9 wherein three flow diagrams illustrating the essential flows of the methods of the present invention for locally and correspondingly performing a number of emulation functions by distributed data processing resources 102 of various logic boards 100 on behalf of and under the direction of the control resources of an emulation system, in accordance with three embodiments, are illustrated.
  • three flow diagrams illustrating the essential flows of the methods of the present invention for locally and correspondingly performing a number of emulation functions by distributed data processing resources 102 of various logic boards 100 on behalf of and under the direction of the control resources of an emulation system, in accordance with three embodiments, are illustrated.
  • the necessary software functions such as those illustrated referencing Fig.
  • distributed data processing resources 102 of various logic boards 100 are also provided with, either at initialization, in conjunction with the requests or combinations thereof, the netlists of their assigned partitions of the IC design to be emulated, including their state as well as combinatorial circuit elements, the mappings between the emulation circuit elements and the "original" circuit elements, and the mappings between the observable emulation signals and the "unobservable” signals, if transformations were performed on some of the circuit elements.
  • Distributed data processing resources 102 of various logic boards 100 are also provided with the identifications of the reconfigurable logic resources of their emulation ICs 104 to be employed to emulate the various circuit elements of the netlists of the assigned partitions.
  • Fig. 7 wherein the method of the present invention for locally and correspondingly determining interconnect routing (within the emulation ICs of a logic board) and generating configuration signals (for board level and within emulation IC interconnects) by distributed data processing resources 102 of various logic boards 100, in accordance with one embodiment, is shown.
  • the method starts with the EDA software 604 executing on workstation 602 reading an IC design to be emulated, block 702.
  • EDA software 604 first partitions the netlists of the IC design into partitions to be emulated by the emulation ICs 104 of the various logic boards 100, assigning the netlists of the various partitions to the various logic boards 100, block 704.
  • EDA software 604 also determines routing on the various logic boards 100 to interconnect the assigned emulation ICs 104 of the logic boards, also block 704. Further, EDA software 604 provides the various logic boards 100 with the relevant assignment and onboard routing information, block 704, as well as requests the interconnect routing within the assigned emulation ICs 104 to be determined locally by the corresponding logic boards 100. Moreover, the configuration bits for configuring the various reconfigurable logic and interconnect resources are to be generated locally by the corresponding logic boards 100. If necessary, the provision and request operations are iteratively re-performed.
  • the router/configuration software Upon receipt of the provided assignment and on-board information, and the on-chip routing and configuration requests, the router/configuration software, executed by distributed data processing resources 102 of each of logic boards 100, locally and correspondingly determine the routing within emulation ICs 104 of logic boards 100 to interconnect the reconfigurable logic resources within the assigned emulation ICs 104 of the logic boards 100 allocated to emulate the circuit elements of the netlists of the partitions of the IC design, block 706. Again, if necessary, the operation is iteratively re- performed.
  • distributed data processing resources 102 of each logic board 100 would locally and correspondingly generate the appropriate configuration bits to configure the allocated emulation resources of the hosted emulation ICs 104, and the on-board resources of logic boards 100 according to the centrally determined partition and board level routing, and locally determined within emulation IC routing, block 708. Similarly, if necessary, the operation is iteratively re-performed.
  • the amount of signals having to be transferred to the various emulation logic boards 100 to configure the emulation resources of their hosted emulation ICs 104 to realize an IC design is advantageously reduced.
  • EDA software 604 facilitates a user in submitting various trace analysis requests, block 814.
  • EDA software 604 determines if additional data from the distributed logic boards 100 are necessary to satisfy the user' request, block 816. If not, response is provided to the user, block 820. On the other hand if additional trace data is required, one or more requests for the trace data are provided to the applicable one or ones of distributed data processing resources 102 of logic boards 100.
  • the trace data requested may include state values of observable as well as "unobservable” signals.
  • the requests include identification of the unobservable signals of interest, the relevant observable emulation signals from which the "unobservable” signals may be inferred, and the functions for use to infer the signal states of the "unobservable” signals of interest from the relevant observable emulation signals.
  • distributed data processing resources 102 of the requested logic boards 100 upon receipt of the trace data requests, locally and correspondingly re-create the "unobservable” emulation signals of interest.
  • distributed data processing resources 102 of various logic boards 100 correspondingly pack and compress the requested observable as well as the "unobservable” signals of the logic boards 100 for return to EDA software 604.
  • EDA software 604 Upon receipt of the packed and compressed observable and "unobservable" signals of interest, EDA software 604 decompresses and unpacks to recover the requested signals of interest. Thereafter, the process continues from block 816 as earlier described.
  • Packing and compression may be practiced using any of these techniques known in the art.
  • EDA software 604 determines if certain test stimuli are to be applied and events are to be monitored, including whether test stimuli are to be generated.
  • EDA software 604 requests selected ones of distributed data processing resources 102 of various logic boards 100 to apply the stimuli of interest, and perform the monitoring, block 918.
  • each of the requests includes the emulation state elements from whose state data the occurrence of the events of interest may be discerned. Further, EDA software 604 determines if the stimuli needs to be generated, if so, the stimuli are generated accordingly.
  • distributed data processing resources 102 of requested logic boards 100 access the relevant emulation state data, block 906.
  • Data processing resources 102 of requested logic boards 100 analyze the retrieved state data to detect occurrences of the events of interest, block 908.
  • distributed data processing resources 102 of the detecting logic boards 100 report the detection or detections accordingly, block 910. Thereafter, the process proceeds as earlier described.
  • emulation IC 104' includes reconfigurable LEs (RLR) 202, reconfigurable interconnects (RIN) 204, emulation memory (MEM) 206, debugging resources (DBR) 208, context or state elements (CTX) 210, and configuration registers (CR) 212 and 214 coupled to each other as before (i.e. through on-chip bus).
  • RLR reconfigurable LEs
  • RIN reconfigurable interconnects
  • MEM emulation memory
  • DBR debugging resources
  • CTX context or state elements
  • CR configuration registers
  • Data processing resources 1002 is provided to supplement data processing 102 provided to logic board 100. Selected ones of the software components illustrated in Fig. 4 are provided to data processing resources 1002 where the corresponding functions are executed on emulation IC 102 in lieu of being executed on host logic board 100. Similarly, trace memory 1004 is provided to augment trace memory 110 provided to host logic board 100. In some embodiment, trace memory 1004 of various emulation ICs 104' completely replace trace memory 110 of a host logic board 100. That is, for these embodiments, trace memory 110 is no longer provided to logic board 100.

Abstract

In accordance with a first aspect, data processing resources are distributively provided to an emulation system to locally and correspondingly generate configuration signals to configure selected ones of reconfigurable logic and interconnect resources of corresponding collections of reconfigurable logic and interconnect resources, to emulate corresponding partitions of an IC design. In accordance with another aspect, data processing resources are also distributively provided to an emulation system to locally and correspondingly generate testing stimuli, and applying the generated testing stimuli to partitions of an IC design to be emulated. In accordance with yet another aspect, data processing resources are distributively provided in an emulation system to locally and correspondingly pre-process collected signal states of signals of partitions of an IC design being emulated, to report on a plurality of the signal states, in response to a request for them. In one embodiment, the distributed data processing resources are disposed on logic boards of an emulation system. In other embodiments, at least some of the distributed data processing resources are disposed on the emulation ICs of the logic boards.

Description

Emulation Components and System Including Distributed Emulation Methods
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of emulation. More specifically, the present invention relates to the components, such as integrated circuits and logic boards, employed to form emulation systems, and various distributed emulation methodologies practiced thereon.
2. Background Information
The first generation of prior art emulation systems were typically formed using general purpose FPGAs without integrated debugging facilities. To emulate a circuit design on one of such emulation systems, the circuit design would be "realized" by compiling a formal description of the circuit design, partitioning the circuit design into subsets, mapping the various subsets to the logic elements (LEs) of the FPGAs of various logic boards of the emulation system, and then configuring and interconnecting the LEs. The partitioning and mapping operations would be typically performed on workstations that are part of or complementary to the emulation systems, while the configuration information would be correspondingly downloaded onto the logic boards hosting the FPGAs, and then onto the FPGAs.
During emulation, test stimuli are either generated on the workstation or on a service board of the emulation system under the control of the workstation, and then transfer to the various logic boards for input into the emulation ICs for application to the various netlists of the IC design being emulated. State data of various circuit elements as well as signal states of interest of the IC design being emulated, would be correspondingly read out of the applicable FPGAs, and then transfer off the logic boards, for analysis on the workstation.
With advances in integrated circuit and emulation technology, some late model emulation systems would employ "FPGAs" specifically designed for emulation purpose. These special "FPGAs" or emulation ICs typically would include substantial amount of on-chip reconfigurable logic elements, inteconnects, memory as well as debugging resources. As the advances continue, more and more of these resources are packed into each emulation IC. As a result, more and more control signals have to be transferred onto each logic board (for transfer into the emulation ICs) to configure the emulation ICs of the logic board. Likewise, more and more state elements and/or signals of interest of the emulation ICs have to be transferred out of the emulation ICs and logic boards to facilitate analysis, leading to the formation of various bottlenecks, in particular, at the logic boards, preventing efficient operation of the emulation systems.
Thus, an improved approach to forming and operating emulation systems is desired.
SUMMARY OF THE INVENTION
In accordance with a first aspect, data processing resources are distributively provided to an emulation system to locally and correspondingly generate configuration signals to configure selected ones of reconfigurable logic and interconnect resources of corresponding collections of reconfigurable logic and interconnect resources, to emulate corresponding partitions of an IC design. In one embodiment, the distributed data processing resources further locally and correspondingly determine inteconnect routing within the selected ones of reconfigurable logic resources of the corresponding collections of reconfigurable logic resources.
In accordance with a second aspect, data processing resources are distributively provided to an emulation system to locally and correspondingly generate testing stimuli, and applying the generated testing stimuli to partitions of an IC design to be emulated. In one embodiment, the distributed data processing resources further locally and correspondingly retrieve state data of emulation state circuit elements, analyze the retrieved state data for one or more events, and report the one or more events upon their detection.
In accordance with a third aspect, data processing resources are distributively provided in an emulation system to locally and correspondingly pre-process captured signal states of signals of partitions of an IC design being emulated to facilitate reporting on a plurality of the signal states, in response to a request for the signal states. In one embodiment, the local and corresponding pre-processing includes local and corresponding re-creation of a plurality of unobservable ones of the requested signal states, based on a number of locally observed ones of the signal states, in accordance with a number of provied mapping functions. In another embodiment, the distributed data processing resources also locally and correspondingly compress the signals of interest, and report the signals in a compressed form to reduce the data transmission bandwidth requirement between the logic boards and the control workstation of the emulation system.
In one embodiment, the distributed data processing resources are disposed on logic boards having emulation ICs that include the reconfigurable logic and interconnect resources. In other embodiments, at least some of the distributed data processing resources are disposed on the emulation ICs. The board and IC disposed distribtued data processing resources cooperatively perform the earlier mentioned distributed emulation methods.
Additionally, the present invention also contemplates the consitution of an emulation system using the aforementioned emulation ICs and logic boards. BRIEF DESCRIPTION OF DRAWINGS
The present invention will be described by way of exemplary embodiments, but not limitations, illustrated in the accompanying drawings in which like references denote similar elements, and in which:
Figure 1 illustrates the major functional blocks of a logic board incorporated with the teachings of the present invention, in accordance with one embodiment;
Figure 2a-2b illustrate a hosted emulation IC of Fig. 1 in further details, including the on-chip debugging resources of the emulation IC in further details, in accordance with one embodiment;
Figure 3 illustrates the on-board data processing resources of Fig. 1 in further details, in accordance with one embodiment;
Figure 4 illustrates an overview of the software modules provided to the data processing resources of Fig. 3 in further details, in accordance with one embodiment; Figure 5 illustrates an example packet suitable for use to communicate with the data processing resources of Fig. 1 , in accordance with one embodiment;
Figure 6 illustrates an emulation system of the present invention, formed with the emulation logic board of the present invention, in accordance with one embodiment;
Figure 7 illustrates the operation flow of a method of the present invention for distributively and correspondingly routing the interconnects for circuit elements of the netlists of a partition of an IC design, and configuring the reconfigurable resources of the emulation system, in accordance with one embodiment;
Figure 8 illustrates the operation flow of a method of the present invention for distributively and correspondingly pre-processing trace data of interest of an IC design being emulated, in accordance with one embodiment;
Figure 9 illustrates the operation flow of a method of the present invention for distributively and correspondingly generating and applying testing stimuli, as well as monitoring for occurrences of selected events, in accordance with one embodiment; and
Figure 10 illustrates a hosted emulation IC of Fig. 1 in further details, in accordance with an alternate embodiment.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well known features are omitted or simplified in order not to obscure the present invention.
Referring now to Figure 1 , where an overview of a logic board incorporated with the teachings of the present invention, in accordance with one embodiment, is illustrated. As shown, for the illustrated embodiment, logic board 100 of the present invention includes on-board data processing resources 102, on-board emulation ICs 104, on-board reconfigurable interconnects 106, on-board bus 108, and on-board trace memory 110 coupled to each other as shown (i.e. through on-board bus 108). Additionally, on-board emulation ICs 104 are also directly coupled to on-board trace memory 110. Logic board 100 further includes a number of I/O pins (not explicitly illustrated). A first subset of which may be employed to couple selected ones of the outputs of reconfigurable interconnects 106 to reconfigurable interconnects of other logic boards (thereby coupling the emulation resources of the logic boards). A second subset of which may be employed to couple data processing resources 102 to certain control resources, such as a control workstation. Accordingly, a novel emulation system may be formed using multiple ones of logic board 100 and control resources, wherein data processing resources 102 of the various logic boards 100 may be employed to locally and correspondingly (i.e. distributively) perform a number of emulation functions on behalf of and at the direction of the control resources. As a result, the operation efficiency of the novel emulation system is improved.
Emulation ICs 104, in particular, their on-chip reconfigurable logic and interconnect resources, as in prior art "FPGAs", are used to "realize" the netlists of an IC design to be emulated. In various embodiment, each emulation IC 104 may advantageously include integrated debugging facilities, such as those included with enhanced "FPGAs" described in USP 5,777,489, and co-pending U.S. Patent Application number 08/542,838, to be described more fully below.
Reconfigurable interconnects 106, as alluded to earlier, facilitate coupling of the emulation resources of the various emulation ICs 104 of the different logic boards 100 employed to form an emulation system. On-board bus 108 and trace memory 110 perform their conventional functions of facilitating on-board communication/data transfers, and collection of signal states of the various emulation signals of the assigned partition of the IC design being emulated.
In various embodiments, the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local determination (at the individual board level) of the routing to interconnect the reconfigurable logic resources of the hosted emulation ICs 104 to be used to emulate the circuit elements of the netlists of the partition of an IC design "assigned" to logic board 100 (i.e. distributive routing of an IC design), as well as local generation (at the board level) of configuration signals to configure the emulation resources of the on-board emulation ICs 104 and other on-board emulation resources, such as reconfigurable interconnects 106 (i.e. distributive configuration of emulation resources). Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to routing and configuration requests from the control resources of the emulation system.
In various embodiments, the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local generation (at the board level) of testing stimuli, and application of the generated testing stimuli to the appropriate "input pins" of the IC design being emulated. In various embodiments, the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local determination (at the board level) of the emulation state elements of an IC design being emulated to be monitored, reading of the state data of the emulation state elements to detect occurrence of certain events, and reporting of the occurrence of the events upon their detection. Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to testing and/or monitor requests from the control resources of the emulation system.
In various embodiments, the emulation functions distributively and correspondingly performed on behalf of, and under the direction of the control resources, by on-board data processing resources 102 (of each logic board 100) include local pre-processing (at the board level) of captured trace data to determine the signal state of one or more signals of interest of the IC design being emulated. Data processing resources 102 distributively and correspondingly perform these emulation functions responsive to trace data requests from the control resources of the emulation system.
The novel manners in which these emulation functions are performed provide at least the advantage of reducing the amount of control signals and data needed to be transferred in and out of emulation logic board 100 to configure emulation resources of emulation ICs 104 to emulate and debug an assigned partition of an IC design. Additionally, the present invention also provides the advantage of speeding up debugging, testing, including co- simulation of a hardware-software design, performed using an emulation system constituted with multiple ones of logic boards 100.
On-board bus 108, reconfigurable interconnects 106, system bus 108 and trace memory 110, are intended to represent a broad range of these elements known in the art, accordingly will not be further described. At least one embodiment each for emulation ICs 104 and data processing resources 102 are described in turn below.
Referring now to Figures 2a-2b, wherein two block diagrams illustrating an emulation IC 104 in further details, in accordance with one embodiment, are shown. As illustrated in Fig. 2a, emulation IC 104 includes reconfigurable LEs (RLR) 202, reconfigurable interconnects (RIN) 204, emulation memory (MEM) 206, debugging resources (DBR) 208, context or state elements (CTX) 210, and configuration registers (CR) 212 and 214 coupled to each other as shown. Reconfigurable LEs 202, emulation memory 206 and context/state elements 210 are used to "realize" circuit elements of the netlists of an assigned partition of an IC design to be emulated. In particular, reconfigurable LEs 202 are used to "realize" the combinatorial logic of the netlists of the assigned partition of an IC design to be emulated. Context/state elements 210 are used to "realize" state elements of the netliest of the assigned partition of the IC design to be emulated, such as flip-flops, and so forth, whereas emulation memory 206 are used to "realize" storage elements of the netlists of the assigned partition of the IC design to be emulated. Reconfigurable interconnects 204 are used to reconfigurbaly couple LEs 202, memory 206 and so forth.
In various embodiments, configuration of these elements, including determination of the interconnect routing, to emulate the netlists of an assigned partition of an IC design, reading of state data of state elements, including determination of which state elements to read, capturing of signal states, includingre-creation of "unobservable" signals, are locally (i.e. distributively) performed by data processing resources 102 of the host logic board 100, to be described more fully below.
Figure 2b illustrates certain aspects of debugging resources 208 of emulation IC 104 in further details in accordance with one embodiment. As illustrated, debugging resources 208 of an emulation IC 104 include scan memory 224 and reconfigurable interconnect 222 reconfigurably coupling scan memory 224 to the reconfigurable logic resources 202 of emulation IC 104. Scan memory 224 outputs to on-board trace memory 110.
Scan memory 224 is designed to operate responsive to a debug clock that is typically faster than the emulation clock. Accordingly, during one emulation clock cycle, scan memory 224 may enable signal states of different signals of the netlists of an assigned partition of an IC design being emulated to be captured.
Except for the novel manner on-board data processing resources 102 control and operate these enumerated elements of emulation IC 104, the various enumerated elements of emulation IC 104 are otherwise known in the art, accordingly will not be further described.
Referring now to Figure 3, wherein a block diagram illustrating on-board data processing resources 102 of one logic board 100 in further details, in accordance with one embodiment, is shown. As illustrated, data processing resources 102, for the embodiment, include processor 302, dynamic random memory 304, and I/O interface 306, coupled to each other as shown. Processor 302, memory 304 and I/O interface 306 are also coupled to the earlier described logic board bus 108. Memory 304 is used to store a "working" copy of the various software for performing the local (i.e. distributive) routing determination, configuration signals generation, event detection, test stimuli generation, as well as preprocessing of captured signal states, and so forth. For the illustrated embodiment, the software is downloaded to memory 304 during initialization. For this embodiment, the download is preferably staged with the software associated with interconnect routing determination and configuration signal generation being downloaded first, while the software associated with distributed debugging and testing operations download later. In alternate embodiment, logic board 100 may additionally be provided with non-volatile storage, such that a "permanent" copy of a subset or all of the requisite software may be stored. Processor 302 is used to execute the software and effectuate performance of the aforementioned functions, whereas I/O interface 306 facilitates communication between processor 302 and other entities external to logic board 100. Except for the novel use of these elements to effectuate provision of the desired advantages, these elements of data processing resources 102 are otherwise known in the art, accordingly will not be further described.
Figure 4 illustrates an overview of the software modules provided to data processing resources 102 to provide the desire functionalities of the present invention to a logic board, in accordance with one embodiment. As illustrated, software 400 includes control module 402, and functional modules, router 403, configurator 404, trace data processor 406, state data/event detector 408, and test stimuli generator 410. Control module 602 is equipped with control logic to facilitate the overall operation in the delivery of the desired functions, including in particular communication with external entities outside a ( logic board 100, and invocation of appropriate ones of the functional modules. In one embodiment, control module 402 communicates with the external entities on a request and response transaction basis, via communication packets. That is, under the present invention, the assigned netlists, as well as the routing, configuration, signal state, state data of state elements, and testing requests are made, acknowledged and responded to using transaction messages sent and received in a series of communication packets. Of course, in alternate embodiments, other communication techniques may be used instead.
Fig. 5 illustrates an example communication packet, in accordance with one embodiment, is shown. As illustrated, communication packet 500 includes packet header 502, command field 504, parameters associated with the specified commands, or pointers to these parameters 506, and end of packet marking 508. Packet header 502 and EOP 508 facilitate provision of various communication related control information, as common in the art of communication. Command 504 facilitates communication between processor 302 and the external entities on the tasks to be performed, and their results. Parameters or pointers thereto 506 augment the commands or return of results, where appropriate.
Referring back to Fig. 4, router 403 is equipped with logic to locally (therefore, correspondingly and distributively) determine the routing for interconnecting the reconfigurable resources of emulation ICs 104 assigned to emulate circuit elements of the netlists of an assigned partition of an IC design to be emulated, responsive to routing requests. Except for the fact that routing of the reconfigurable resources of emulation ICs 104 of a logic board is locally performed on the "assigned" logic board, the tasks of routing, in and of themselves, are otherwise substantially the same when they are centrally performed on a control workstation of an emulation system, and known in the art.
Configurator 404 is equipped with logic to locally (therefore, correspondingly and distributively) generate the configuration bits necessary to configure the reconfigurable logic and interconnect resources of emulation ICs 104, and the applicable interconnect resources of the logic board, in accordance with the reconfigurable logic resources and board level inteconnect centrally determined and the reconfigurable interconnect within the emulation ICs 104 locally determined, responsive to configuration requests. Similarly, except for the fact that generation of the configuration bits is locally performed on the "assigned" logic board, the tasks of generating configuration bits in accordance with a resource allocation, in and of itself, is otherwise substantially the same as the tasks are centrally performed on a control workstation of an emulation system, and also known in the art.
Trace data processor 406 is equipped with logic to locally pre-processes the captured signal states of the emulation signals to determine one or more signal states of one or more signals of interest of the netlists of the assigned partition of the IC design being emulated, responsive to trace data requests. Again, except for the fact that the captured signal states of the emulation signals are pre-processed locally, reconfiguration of debugging resources and processing of capture signal states, in and of themselves, are otherwise substantially the same as these tasks are centrally performed on a control workstation of an emulation system, and also known in the art.
State data/event monitor 408 is equipped with logic to monitor emulation state elements to detect one or more events. State data/event monitor 408 is further equipped to report the occurrences of the events upon detecting their occurrences. Test vector generator/applicator 410 is equipped with logic to locally (therefore, correspondingly and distributively) generate and apply testing stimuli to the netlists of the assigned partition of the IC design being emulated. Test vector generator/applicator 410 is intended to represent a broad range of testing software known in the art. Similarly, except for the fact that retrieval of state data, event detection, generation and application of test stimuli are locally performed, each of these operations, in and of itself, is substantially the same as the operation is centrally performed at the control workstation.
Referring now to Figure 6, wherein a block diagram of an emulation system formed using logic boards 100 incorporated with the teachings of the present invention, in accordance with one embodiment, is shown. As illustrated, emulation system 600 includes control workstation 602 and emulator 606. Control workstation 602 is equipped with EDA software 604. Emulator 606 includes a number of logic boards 100, each having a number of emulation ICs 104 and on-board data processing resources 102 disposed there on as described earlier. In addition to logic boards 100, emulator 606 also includes service and I/O boards 608. Boards 100 and 608 are interconnected by inter-board interconnects 610. In one embodiment, various boards 100 and 608 are packaged together to form a crate (not shown), and the crates are interconnected together via inter-board interconnect 610. The precise numbers of emulation ICs 104 disposed on each board, as well as the precise manner in which the various boards are packaged into crates are unimportant, and application dependent.
EDA software 604 is incorporated with the teachings of the present invention, in particular, the corresponding distribution of emulation logic board level routing of the interconnects for netlists of the various partitions of an IC design to be emulated, and configuration of the emulation resources of the emulation ICs of a logic board, to the logic boards themselves. Except for the teachings of the present invention incorporated, EDA software 604 is otherwise intended to represent a broad range of the software typically supplied with an emulation system, including in particular the software for partitioning the netlists of an IC design to be emulated at the system level, and the software for debugging and testing an IC design being emulated, such as model simulators.
Similarly, except for the employment of emulation logic boards 100, thereby providing the desired advantages, emulator 606 is also intended to otherwise represent a broad range of emulators known in the art.
Referring now to Figures 7-9, wherein three flow diagrams illustrating the essential flows of the methods of the present invention for locally and correspondingly performing a number of emulation functions by distributed data processing resources 102 of various logic boards 100 on behalf of and under the direction of the control resources of an emulation system, in accordance with three embodiments, are illustrated. For these embodiments, in addition to the provision of the necessary software functions, such as those illustrated referencing Fig. 4, distributed data processing resources 102 of various logic boards 100 are also provided with, either at initialization, in conjunction with the requests or combinations thereof, the netlists of their assigned partitions of the IC design to be emulated, including their state as well as combinatorial circuit elements, the mappings between the emulation circuit elements and the "original" circuit elements, and the mappings between the observable emulation signals and the "unobservable" signals, if transformations were performed on some of the circuit elements. Distributed data processing resources 102 of various logic boards 100 are also provided with the identifications of the reconfigurable logic resources of their emulation ICs 104 to be employed to emulate the various circuit elements of the netlists of the assigned partitions.
Referring now to Fig. 7, wherein the method of the present invention for locally and correspondingly determining interconnect routing (within the emulation ICs of a logic board) and generating configuration signals (for board level and within emulation IC interconnects) by distributed data processing resources 102 of various logic boards 100, in accordance with one embodiment, is shown. As illustrated, the method starts with the EDA software 604 executing on workstation 602 reading an IC design to be emulated, block 702. EDA software 604 first partitions the netlists of the IC design into partitions to be emulated by the emulation ICs 104 of the various logic boards 100, assigning the netlists of the various partitions to the various logic boards 100, block 704. For the embodiment, EDA software 604 also determines routing on the various logic boards 100 to interconnect the assigned emulation ICs 104 of the logic boards, also block 704. Further, EDA software 604 provides the various logic boards 100 with the relevant assignment and onboard routing information, block 704, as well as requests the interconnect routing within the assigned emulation ICs 104 to be determined locally by the corresponding logic boards 100. Moreover, the configuration bits for configuring the various reconfigurable logic and interconnect resources are to be generated locally by the corresponding logic boards 100. If necessary, the provision and request operations are iteratively re-performed.
Upon receipt of the provided assignment and on-board information, and the on-chip routing and configuration requests, the router/configuration software, executed by distributed data processing resources 102 of each of logic boards 100, locally and correspondingly determine the routing within emulation ICs 104 of logic boards 100 to interconnect the reconfigurable logic resources within the assigned emulation ICs 104 of the logic boards 100 allocated to emulate the circuit elements of the netlists of the partitions of the IC design, block 706. Again, if necessary, the operation is iteratively re- performed.
Further, distributed data processing resources 102 of each logic board 100 would locally and correspondingly generate the appropriate configuration bits to configure the allocated emulation resources of the hosted emulation ICs 104, and the on-board resources of logic boards 100 according to the centrally determined partition and board level routing, and locally determined within emulation IC routing, block 708. Similarly, if necessary, the operation is iteratively re-performed.
As a result, as alluded to earlier, the amount of signals having to be transferred to the various emulation logic boards 100 to configure the emulation resources of their hosted emulation ICs 104 to realize an IC design is advantageously reduced.
Referring now to Fig. 8, wherein the method of the present invention for locally and correspondingly preprocess captured trace data of interest by distributed data processing resources 102 of various logic boards 100, in accordance with one embodiment, is shown. As illustrated, EDA software 604 facilitates a user in submitting various trace analysis requests, block 814. In response to the submission of a user request, EDA software 604 determines if additional data from the distributed logic boards 100 are necessary to satisfy the user' request, block 816. If not, response is provided to the user, block 820. On the other hand if additional trace data is required, one or more requests for the trace data are provided to the applicable one or ones of distributed data processing resources 102 of logic boards 100. In one embodiment, the trace data requested may include state values of observable as well as "unobservable" signals. For "unobservable" signals, the requests include identification of the unobservable signals of interest, the relevant observable emulation signals from which the "unobservable" signals may be inferred, and the functions for use to infer the signal states of the "unobservable" signals of interest from the relevant observable emulation signals. At block 804, distributed data processing resources 102 of the requested logic boards 100, upon receipt of the trace data requests, locally and correspondingly re-create the "unobservable" emulation signals of interest. At block 806, upon re-creating the "unobservable" signals, distributed data processing resources 102 of various logic boards 100 correspondingly pack and compress the requested observable as well as the "unobservable" signals of the logic boards 100 for return to EDA software 604.
Upon receipt of the packed and compressed observable and "unobservable" signals of interest, EDA software 604 decompresses and unpacks to recover the requested signals of interest. Thereafter, the process continues from block 816 as earlier described.
Packing and compression may be practiced using any of these techniques known in the art.
Referring now to Fig. 9, wherein the method of the present invention for locally and correspondingly generating and applying testing stimuli as well as monitoring for occurrence of certain events by distributed data processing resources 102 of various logic boards 100, in accordance with one embodiment, is shown. As illustrated, EDA software 604, more specifically, various simulation models are executed on control workstation 602, block 914. At block 916, EDA software 604 determines if certain test stimuli are to be applied and events are to be monitored, including whether test stimuli are to be generated.
If certain stimuli are to be applied and occurrences of certain events are to be monitored, EDA software 604 requests selected ones of distributed data processing resources 102 of various logic boards 100 to apply the stimuli of interest, and perform the monitoring, block 918. In one embodiment, each of the requests includes the emulation state elements from whose state data the occurrence of the events of interest may be discerned. Further, EDA software 604 determines if the stimuli needs to be generated, if so, the stimuli are generated accordingly.
Thus, upon receipt of the request, distributed data processing resources 102 of requested logic boards 100 access the relevant emulation state data, block 906. Data processing resources 102 of requested logic boards 100 analyze the retrieved state data to detect occurrences of the events of interest, block 908. Upon detecting one or more occurrences of the events of interest, distributed data processing resources 102 of the detecting logic boards 100 report the detection or detections accordingly, block 910. Thereafter, the process proceeds as earlier described.
Referring now to Figure 10, wherein a block diagram illustrating an emulation IC 104', in accordance with an alternate embodiment, is shown. As illustrated, emulation IC 104' includes reconfigurable LEs (RLR) 202, reconfigurable interconnects (RIN) 204, emulation memory (MEM) 206, debugging resources (DBR) 208, context or state elements (CTX) 210, and configuration registers (CR) 212 and 214 coupled to each other as before (i.e. through on-chip bus). However, for this embodiment, emulation IC 104' additionally include data processing resources 1002 and trace memory 1004. Further, debugging resources (DBR) 208 are directly coupled to on-chip trace memory 1004.
Data processing resources 1002 is provided to supplement data processing 102 provided to logic board 100. Selected ones of the software components illustrated in Fig. 4 are provided to data processing resources 1002 where the corresponding functions are executed on emulation IC 102 in lieu of being executed on host logic board 100. Similarly, trace memory 1004 is provided to augment trace memory 110 provided to host logic board 100. In some embodiment, trace memory 1004 of various emulation ICs 104' completely replace trace memory 110 of a host logic board 100. That is, for these embodiments, trace memory 110 is no longer provided to logic board 100.
Except for their disposition on emulation IC 102, their constitutions and functions are substantially the same as their earlier described board disposed counterpart.
Thus, emulation components including emulation IC and logic boards, and an emulation system constituted with such components, including distributed and local capture of trace data and pre-processing of the captured trace data have been described. While the method and integrated circuit of the present invention has been described in terms of the above illustrated embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described. The present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. For example, the various novel features described may be packaged in finer or coarser units of form factors. The description is thus to be regarded as illustrative instead of restrictive on the present invention.

Claims

What is claimed is: 1. An emulation logic board designed for circuit emulation, comprising a plurality of input/output (I/O) pins; a plurality of emulation integrated circuits (IC) having reconfigurable logic resources and reconfigurable interconnect resources; and on-board data processing resources coupled said emulation ICs to locally generate and apply first configuration signals to configure selected ones of said reconfigurable logic resources of said emulation ICs to be used to emulate a partition of an IC design, and second configuration signals to configure selected ones of said reconfigurable interconnect resources of said emulation ICs to interconnect said selected ones of said reconfigurable logic resources of said emulation ICs, responsive to external emulation requests received through said I/O pins.
2. The emulation logic board as set forth in claim 1 , wherein the on-board data processing resources comprise storage medium having stored therein programming instructions designed to operate the emulation logic board to perform said local generation and application of configuration signals to configure said selected ones of said reconfigurable logic and interconnect resources of said emulation ICs, and a processor coupled to the storage medium to execute said programming instructions.
3. The emulation logic board as set forth in claim 1 , wherein said on-board data processing resources further receive through said I/O pins said partition of an IC design, and locally determine interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs to be used to emulate said partition of an IC design.
4. The emulation logic board as set forth in claim 3, wherein the on-board data processing resources comprise storage medium having stored therein programming instructions designed to operate the emulation logic board to perform said local determination of routing within said selected ones of said reconfigurable logic resources of said emulation ICs, and a processor coupled to the storage medium to execute said programming instructions.
5. The emulation logic board as set forth in claim 1 , wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources to perform said local generation and application of configuration signals.
6. The emulation logic board as set forth in claim 5, wherein said on-board data processing resources further receive through said I/O pins said partition of an IC design, and locally determine interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs to be used to emulate said partition of an IC design; and at least one of said on-chip data processing resources of said at least one emulation IC further cooperates and assists said on-board data processing resources to perform said local determination of interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs to be used to emulate said partition of an IC design.
7. An emulation system comprising: a workstation including electronic design automation (EDA) software to partition an integrated circuit (IC) design into a plurality of partitions; and an emulator including a plurality of logic boards, coupled to said workstation, each of said logic boards having a plurality of emulation ICs and on-board data processing resources, and each of said emulation ICs having reconfigurable logic and interconnect resources, wherein each of the on-board data processing resources include logic to correspondingly and distributively generate configure signals to configure selected ones of said reconfigurable logic and interconnect resources of its emulation ICs, to facilitate emulation of said IC design, responsive to emulation requests of said EDA software.
8. The emulation system as set forth in claim 7, wherein the on-board data processing resources comprise storage medium having stored therein programming instructions designed to operate the emulation logic board to perform said local generation and application of configuration signals to configure said selected ones of said reconfigurable logic and interconnect resources of said emulation ICs of said emulation logic board, and a processor coupled to the storage medium to execute said programming instructions.
9. The emulation system as set forth in claim 7, wherein said on-board data processing resources further receive said partition of an I C design from said EDA software, and locally determine interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs of said emulation logic board to be used to emulate said partition of an IC design.
10. The emulation system as set forth in claim 9, wherein the on-board data processing resources comprise storage medium having stored therein programming instructions designed to operate the emulation logic board to perform said local determination of routing within said selected ones of said reconfigurable logic resources of said emulation ICs of said emulation logic board, and a processor coupled to the storage medium to execute said programming instructions.
11. The emulation system as set forth in claim 7, wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources of said emulation logic board to perform said local generation and application of configuration signals.
12. The emulation system as set forth in claim 11 , wherein said on-board data processing resources of said emulation logic board further receive said partition of an IC design from said EDA software, and locally determine interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs to be used to emulate said partition of an IC design; and at least one of said on-chip data processing resources of said at least one of said emulation ICs of said emulation logic board further cooperates and assists said on-board data processing resources of said emulation logic board to perform said local determination of interconnect routing within said selected ones of said reconfigurable logic resources of said emulation ICs of said emulation logic board to be used to emulate said partition of an IC design.
13. An emulation apparatus comprising: a plurality of collections of reconfigurable logic and interconnect resources; and a plurality of groups of data processing resources correspondingly coupled to said collections of reconfigurable logic and interconnect resources to correspondingly and distributively generate configuration signals to configure selected ones of reconfigurable logic and interconnect resources to emulate circuit elements of corresponding partitions of an IC design.
14. The emulation apparatus as set forth in claim 13, wherein at least one group of the data processing resources comprises storage medium having stored therein programming instructions designed to perform said corresponding and distributive generation of configuration signals, and a processor coupled to the storage medium to execute the programming instructions.
15. The emulation apparatus as set forth in claim 13, wherein at least one group of the data processing resources further correspondingly and distributively determine interconnect routing for selected ones of the corresponding collection of reconfigurable logic resources.
16. The emulation apparatus as set forth in claim 15, wherein at least one group of data processing resources comprises storage medium having stored therein programming instructions designed to perform said corresponding and distributed determination of interconnect routing.
17. An emulation integrated circuit (IC) comprising: a plurality of reconfigurable logic and interconnect resources; and on-chip data processing resources coupled to said reconfigurable logic and interconnect resources to locally generate configuration signals to configure selected ones of said reconfigurable logic and interconnect resources of said emulation IC to emulate circuit elements of a partition of an IC design.
18. The emulation IC as set forth in claim 17, wherein said on-chip data processing resources comprises storage medium having stored therein programming instructions designed to perform said local generation of configuration signals, and a processor coupled to the storage medium to execute the programming instructions.
19. The emulation IC as set forth in claim 17, wherein said on-chip data processing resources further locally determine interconnect routing within said selected ones of said reconfigurable logic resources of said emulation IC.
20. The emulation IC as set forth in claim 19, wherein said on-chip data processing resources comprises storage medium having stored therein programming instructions designed to perform said local determination of interconnect routing.
21. A logic board designed for circuit emulation, comprising a plurality of input/output (I/O) pins; a plurality of emulation integrated circuits (IC), each having reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of a partition of an IC design; and a plurality of on-board data processing resources coupled to said emulation ICs to locally retrieve from said emulation ICs state data of emulation state circuit elements, responsive to a monitor and report request received through said I/O pins, and to locally analyze the retrieved state data to detect occurrence of one or more events, as well as report on the occurrence of the one or more events upon their detection through said I/O pins.
22. The logic board as set forth in claim 21 , wherein the on-board data processing resources comprise a storage medium having stored therein programming instructions designed to operate the logic board to perform said responsive local retrieval of state data of the emulation state circuit elements, local analysis of the retrieved state data, and reporting of event detection, and a processor coupled to the storage medium to execute the programming instructions.
23. The logic board as set forth in claim 21 , wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources to perform said local monitoring and reporting of monitored events.
24. The logic board as set forth in claim 21 , wherein the on-board data processing resources are further employed to locally generate a plurality of testing stimuli, and locally apply said locally generated testing stimuli to the partition of the IC design being emulated, responsive to a testing request received through said I/O pins.
25. The logic board as set forth in claim 24, wherein the on-board data processing resources comprise a storage medium having stored therein programming instructions designed to operate the logic board to perform said responsive local generation and application of stimuli, and a processor coupled to the storage medium to execute the programming instructions.
26. The logic board as set forth in claim 24, wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources to perform said local generation and application of testing stimuli.
27. A logic board designed for circuit emulation, comprising a plurality of input/output (I/O) pins; a plurality of emulation integrated circuits (IC), each having reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of a partition of an IC design; and a plurality of on-board data processing resources coupled to said emulation ICs to locally generate a plurality of testing stimuli, and locally apply said locally generated testing stimuli to emulation circuit elements of said partition of the IC design being emulated, responsive to an external testing request received through said I/O pins.
28. The logic board as set forth in claim 27, wherein the on-board data processing resources comprise a storage medium having stored therein programming instructions designed to operate the logic board to perform said responsive local generation and application of stimuli, and a processor coupled to the storage medium to execute the programming instructions.
29. The logic board as set forth in claim 28, wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources to perform said local generation and application of testing stimuli.
30. An emulation system comprising: a plurality of logic boards, each having a plurality of emulation integrated circuits (IC) including reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of partitions of an IC design, and onboard data processing resources to locally and correspondingly retrieving state data of emulation state circuit elements from the emulation ICs, responsive monitor and report requests received through input/output (I/O) pins of the logic boards, and retrieving state data of the emulation state circuit elements from the emulation ICs, locally and correspondingly analyzing the retrieved state data for one or more events, and reporting occurrence of the one or more events through said I/O pins upon their detection; and a workstation coupled to the logic board electronic design automation (EDA) software to provide said logic boards with said monitor and report requests.
31. The emulation system as set forth in claim 30, wherein the on-board data processing resources of each of the emulation IC comprise storage medium having stored therein programming instructions to operate the logic board to perform said local and corresponding retrieval, analysis, and reporting.
32. The emulation system as set forth in claim 31 , wherein at least one of said emulation ICs of said logic boards comprises on-chip data processing resources to cooperate and assist the on-board data processing resources of the logic board to perform said local and corresponding retrieval, analysis, and reporting.
33. An emulation system comprising: a plurality of logic boards, each having a plurality of emulation integrated circuits (IC) including reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of partitions of an IC design, and on- board data processing resources to locally and correspondingly generate testing stimuli, and apply the generated stimuli to the emulated circuit elements of the partitions of the IC design being emulated, responsive to testing requests received through input/output (I/O) pins of the logic boards; and a workstation coupled to the logic board, including electronic design automation (EDA) software to provide said logic boards with said testing requests.
34. The emulation system as set forth in claim 33, wherein the on-board data processing resources of each of the logic board comprise storage medium having stored therein programming instructions designed to operate the logic board to perform said local and corresponding generation and application of testing stimuli.
35. The emulation system as set forth in claim 33, wherein at least one of said emulation ICs of said logic boards comprises on-chip data processing resources to cooperate and assist the on-board data processing resources of the logic board to perform said local and corresponding generation and application of testing stimuli.
36. An emulation integrated circuit (IC) comprising: a plurality of reconfigurable logic and interconnect resources; and on-chip data processing resources coupled to said reconfigurable logic and interconnect resources to locally retrieve state data of emulation state circuit elements of a partition of an IC design being emulated to monitor, analyze the retrieved state data of the emulation state circuit elements to detect occurrence of one or more events, and report on occurrence of said one or more events upon detecting their occurrence.
37. The emulation IC as set forth in claim 36 wherein said on-chip data processing resources comprises storage medium having stored therein programming instructions designed to perform said local analysis and reporting.
38. The emulation IC as set forth in claim 37, wherein said on-chip data processing resources further locally generate testing stimuli, and locally apply the generated testing stimuli to the partition of the IC design being emulated.
39. The emulation IC as set forth in claim 38, wherein said on-chip data processing resources comprises storage medium having stored therein programming instructions designed to perform said local generation and application of testing stimuli.
40. An emulation integrated circuit (IC) comprising: a plurality of reconfigurable logic and interconnect resources; and on-chip data processing resources coupled to said reconfigurable logic and interconnect resources to locally generate testing stimuli, locally apply the generated testing stimuli to a partition of an IC design being emulated.
41. The emulation IC as set forth in claim 40, wherein said on-chip data processing resources comprises storage medium having stored therein programming instructions designed to perform said local generation and application of testing stimuli.
42. A logic board designed for circuit emulation, comprising a plurality of input/output (I/O) pins; a plurality of emulation integrated circuits (IC), each having reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of a partition of an IC design, and reconfigurable debugging resources to reconfigurably collect signal states of selected subsets of signals of said partition of an IC design being emulated; and a plurality of on-board data processing resources coupled to said emulation ICs to receive through said I/O pins a plurality of signal state requests for signal states of signals of said partition of said IC design being emulated, and in response, pre-process collected signal states of signals of said partition of said IC design being emulated, including re-creation of unobservable ones of the signal states requested, and report through said I/O pins the requested signal states.
43. The logic board as set forth in claim 42, wherein the on-board data processing resources comprise a storage medium having stored therein programming instructions designed to operate the logic board to perform said responsive pre-processing and reporting, and a processor coupled to the storage medium to execute the programming instructions.
44. The logic board as set forth in claim 42, wherein at least one of said emulation ICs comprises on-chip data processing resources to cooperate and assist said on-board data processing resources to perform said responsive preprocessing and reporting of signal states of one or more signals of said partition of an IC design being emulated.
45. The logic board as set forth in claim 42, wherein said re-creating of said unobservable ones of the signal states requested comprises re-creating said unobservable ones of the signal states of the requested signals of the partition of the IC design being emulated, based on a number of locally observed signals states of signals of the partition of the IC design being emulated, in accordance with a number of mapping functions provided with said requests.
46. The logic board as set forth in claim 42, wherein said pre-processing by the on-board data processing resources further comprises compressing the requested signal states to be reported.
47. An emulation system comprising: a plurality of logic boards, each having a plurality of emulation integrated circuits (IC) including reconfigurable logic and interconnect resources reconfigurable to emulate circuit elements of partitions of an IC design and reconfigurable debugging resources to reconfigurably collect signal states of selected subsets of signals of said partitions of an IC design being emulated, and on-board data processing resources to locally and correspondingly pre- process on said logic boards collected signal states of signals of said partitions of said IC design being emualted, including re-creating unobservable ones of requested signal states of signals of said partitions of said IC design being emulated, and report through input/output (I/O) pins of the logic boards the requested signal states, responsive to signal state requests received through said I/O pins of the logic boards; and a workstation coupled to the logic boards, including electronic design automation (EDA) software to provide said logic boards with said signal state requests.
48. The emulation system as set forth in claim 47, wherein the on-board data processing resources of each logic board comprise a storage medium having stored therein programming instructions designed to operate the logic board to perform said responsive pre-processing and reporting, and a processor coupled to the storage medium to execute the programming instructions.
49. The emulation system as set forth in claim 47, wherein at least one of said emulation ICs of one of said logic boards comprises on-chip data processing resources to cooperate and assist the on-board data processing resources of the logic board to perform said responsive pre-processing and reporting of signal states of one or more signals of said partition of an IC design being emulated.
50. The emulation system as set forth in claim 47, wherein said re-creating comprises re-creating unobservable ones of the requested signal states of signals of the partitions of the IC design being emulated, based on a number of locally observed signal states of signals of the partitions of the IC design being emulated, in accordance with a number of mapping functions provided with the requests.
51. The emulation system as set forth in claim 47, wherein said preprocessing by the on-board data processing resources of each logic board further comprises the on-board data processing resources locally compressing the requested signal states to be reported.
52. An emulation integrated circuit (IC) comprising: a plurality of reconfigurable logic and interconnect resources; a plurality of reconfigurable debugging resources coupled to the reconfigurable logic and interconnect resources to reconfigurably collect signal states of emulation signals of a partition of an IC design being emulated by selected ones of said reconigurable logic and interconnect resources; and on-chip data processing resources coupled to said reconfigurable debugging resources to locally pre-process the collected signal states of signals of the partition of an IC design being emulated, to facilitate responsive reporting of signal states of a plurality of requested signal states of signals of the partition of the IC design being emulated, including re-creating unobservable ones of the requested signal states.
53. The emulation IC as set forth in claim 52, wherein said on-chip data processing resources re-create the unobservable requested signal states of signals of the partition of the IC design being emulated, based on locally observed ones of the signal states of the signals of the partition of the IC design being emulated, and in accordance with a plurality of mapping functions provided as part of the request.
54. The emulation IC as set forth in claim 52, wherein said on-chip data processing resources further locally compress the requested signal states to be reported.
PCT/US2002/034690 2001-10-30 2002-10-29 Emulating components and system including distributed emulation methods WO2003038613A1 (en)

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US10/003,184 2001-10-30
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1629380A2 (en) * 2003-06-05 2006-03-01 Mentor Graphics Corporation Compression of emulation trace data

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5572710A (en) * 1992-09-11 1996-11-05 Kabushiki Kaisha Toshiba High speed logic simulation system using time division emulation suitable for large scale logic circuits
US5870586A (en) * 1996-01-31 1999-02-09 Xilinx, Inc. Configuration emulation of a programmable logic device
US5943490A (en) * 1997-05-30 1999-08-24 Quickturn Design Systems, Inc. Distributed logic analyzer for use in a hardware logic emulation system
US6002861A (en) * 1988-10-05 1999-12-14 Quickturn Design Systems, Inc. Method for performing simulation using a hardware emulation system
US6282503B1 (en) * 1994-09-09 2001-08-28 Hitachi, Ltd. Logic emulation system
US6388465B1 (en) * 1995-10-13 2002-05-14 Jean Barbier Reconfigurable integrated circuit with integrated debussing facilities and scalable programmable interconnect

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6002861A (en) * 1988-10-05 1999-12-14 Quickturn Design Systems, Inc. Method for performing simulation using a hardware emulation system
US5572710A (en) * 1992-09-11 1996-11-05 Kabushiki Kaisha Toshiba High speed logic simulation system using time division emulation suitable for large scale logic circuits
US6282503B1 (en) * 1994-09-09 2001-08-28 Hitachi, Ltd. Logic emulation system
US6388465B1 (en) * 1995-10-13 2002-05-14 Jean Barbier Reconfigurable integrated circuit with integrated debussing facilities and scalable programmable interconnect
US5870586A (en) * 1996-01-31 1999-02-09 Xilinx, Inc. Configuration emulation of a programmable logic device
US5943490A (en) * 1997-05-30 1999-08-24 Quickturn Design Systems, Inc. Distributed logic analyzer for use in a hardware logic emulation system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1629380A2 (en) * 2003-06-05 2006-03-01 Mentor Graphics Corporation Compression of emulation trace data
EP1629380A4 (en) * 2003-06-05 2011-05-18 Mentor Graphics Corp Compression of emulation trace data
US8099273B2 (en) 2003-06-05 2012-01-17 Mentor Graphics Corporation Compression of emulation trace data

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