Digital logic simulation/emulation system

• US 5,748,875 A
• Filed: 06/12/1996
• Issued: 05/05/1998
• Est. Priority Date: 06/12/1996
• Status: Expired due to Fees

• Current Assignee: Simpod, Inc.
• Original Assignee: Simpod, Inc.
• Inventors: Tzori, Yifatch
• Primary Examiner(s): Nguyen, Hoa T.
• Application Number:
  US08/661,991
• Time in Patent Office: 692 Days
• Field of Search: 395/183.05, 395/183.04, 395/183.08, 395/183.15, 395/183.22, 395/183.02, 371/22.1, 371/22.2, 364/221.2, 364/232.3, 364/264.3
• US Class Current: 714/29
• CPC Class Codes: G06F 11/261 by simulating additional hardware, e.g. fault simulation
• CPC Class Codes: G06F 30/331 with hardware acceleration, e.g. by using field programmable gate array [FPGA] or emulation

Abstract

A digital logic simulation/emulation system, that includes a hardware pod having a configurable-logic IC arranged to provide a plurality of stimulus/response cells, is adapted for coupling to a digital logic circuit. The stimulus/response cells, which provide stimulus signals to the digital logic circuit, connect to form a shift-register for downloading stimulus-control data, and for uploading response data during a stimulation-response cycle. A logic-configuration library stores configuration-data for establishing a bit-slice architecture for the stimulus/response cells. To facilitate preparing the configuration-data, the system also includes a configurable-logic-specification process having a GUI user interface. The logic-specification process assigns pre-established, bit-slice configuration data for each logic-function cell to specific locations throughout a configurable-logic IC to achieve swift compilation of configuration data.

Claims

1. A digital logic simulation/emulation system comprising:

a computer program digital-logic simulation process executed by a digital computer for modeling a digital logic system;

a hardware pod that;

is adapted for being coupled to a digital logic circuit;

includes a configurable-logic integrated circuit ("IC") which is arranged to include a plurality of stimulus/response cells for providing stimulus signals to the digital logic circuit during a stimulation-response cycle, and for receiving responses from the digital logic circuit during the stimulation-response cycle; and

further includes a communication port for receiving stimulation-control data to be transmitted to the configurable-logic IC for controlling stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for receiving for transmission from said hardware pod response data which the configurable-logic IC receives from the digital logic circuit in response to stimulation thereof during the stimulation-response cycle; and

a server process, coupled both to said digital-logic simulation process and to said hardware pod, for exchanging stimulation-control data and response data between said digital-logic simulation process and said hardware pod, whereby said digital-logic simulation process may transmit stimulation-control data through said server process to said hardware pod for controlling stimulation of the digital logic circuit by the stimulus/response cells during the stimulation-response cycle, and whereby said digital-logic simulation process may receive from said hardware pod through said server process response data from stimulus/response cells of the configurable-logic IC that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

2. The digital logic simulation/emulation system of claim 1 further comprising a logic-configuration library which stores a configuration-data file that contains logic-configuration data which, upon being loaded into the configurable-logic IC of said hardware pod, establishes the plurality of stimulus/response cells in said configurable-logic IC, said logic-configuration library being coupled to said server process whereby said server process may retrieve the configuration-data file from said logic-configuration library and transmit the logic-configuration data to said hardware pod for configuring the configurable-logic IC.

3. The digital logic simulation/emulation system of claim 2 wherein the logic-configuration data, upon being loaded into the configurable-logic IC of said hardware pod, also establishes within the configurable-logic IC, in addition to the plurality of stimulus/response cells:

a state machine for controlling the operation of the configurable-logic IC in providing stimulus signals to the digital logic circuit and in receiving responses from the digital logic circuit; and

a timing generator controlled by the state machine which establishes time intervals within the stimulation-response cycle during which individual stimulus/response cells either provides a stimulus signal to the digital logic circuit and/or receive a response from the digital logic circuit.

4. The digital logic simulation/emulation system of claim 3 further comprising:

a configurable-logic cell-library which stores configuration data that specifies various different types of individual stimulus/response cells; and

a configurable-logic-specification process, coupled both to said configurable-logic cell-library and to said logic-configuration library, which provides a user interface that permits;

selecting an individual stimulus/response cell from the configurable-logic cell-library for inclusion into a configuration-data file to be stored into said logic-configuration library;

specifying a location for the selected stimulus/response cell with respect to the digital logic circuit;

specifying a time interval within the stimulation-response cycle during which the selected stimulus/response cell is to operate for providing a stimulus signal to the digital logic circuit and/or receiving a response from the digital logic circuit;

aggregating a plurality of selected and specified stimulus/response cells into a configuration-data file that may be stored into said logic-configuration library; and

storing the configuration-data file thus aggregated into said logic-configuration library.

5. The digital logic simulation/emulation system of claim 2 wherein the stimulus/response cells established upon loading the configuration-data file into the configurable-logic IC of said hardware pod form a bit-slice architecture in which stimulus/response cells are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

6. The digital logic simulation/emulation system of claim 2 wherein the stimulus/response cells established upon loading the configuration-data file into the configurable-logic IC of said hardware pod are divided into a plurality of separate stimulus/response-cell groups, the stimulus/response cells of each separate stimulus/response-cell group forming a bit-slice architecture in which stimulus/response cells of the stimulus/response-cell group are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

7. The digital logic simulation/emulation system of claim 6 wherein there are four (4) separate stimulus/response-cell groups.

8. The digital logic simulation/emulation system of claim 1 wherein the stimulus/response cells form a bit-slice architecture in which stimulus/response cells are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

9. The digital logic simulation/emulation system of claim 1 wherein the stimulus/response cells are divided into a plurality of separate stimulus/response-cell groups, the stimulus/response cells of each separate stimulus/response-cell group forming a bit-slice architecture in which stimulus/response cells of the stimulus/response-cell group are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

10. The digital logic simulation/emulation system of claim 9 wherein there are four (4) separate stimulus/response-cell groups.

11. The digital logic simulation/emulation system of claim 1 wherein the hardware pod further includes:

a random access memory ("RAM") for storing stimulation-control data for a sequence of successive stimulation-response cycles including stimulation-control data for an initial stimulation-response cycle and stimulation-control data for a final stimulation-response cycle; and

means for selecting stimulation-control data for successive stimulation-response cycles from the RAM beginning with the initial stimulation-response cycle and ending with the final stimulation-response cycle, and for transmitting each successive stimulation-control data to the configurable-logic IC for providing the digital logic circuit with a sequence of stimulus signals, the hardware pod transmitting response data for the final stimulation-response cycle in the sequence of stimulus signals to said server process for re-transmission to said digital-logic simulation process.

12. The digital logic simulation/emulation system of claim 1 wherein a computer program executed by a digital computer provides the server process.

13. The digital logic simulation/emulation system of claim 12 wherein the computer program digital-logic simulation process and the computer program server process are both executed by the same digital computer.

14. The digital logic simulation/emulation system of claim 12 wherein the computer program digital-logic simulation process and the computer program server process are executed by different digital computers.

15. A hardware pod that is adapted for being coupled to a digital logic circuit, and is also adapted for incorporation into a digital logic simulation/emulation system that includes a computer program digital-logic simulation process executed by a digital computer for modeling a digital logic system, the digital logic simulation/emulation system also including a server process, coupled both to the digital-logic simulation process and to the hardware pod, for exchanging stimulation-control data and response data between the digital-logic simulation process and the hardware pod, the hardware pod comprising:

a configurable-logic IC which is arranged to include a plurality of stimulus/response cells for providing stimulus signals to the digital logic circuit during a stimulation-response cycle, and for receiving responses from the digital logic circuit during the stimulation-response cycle; and

a communication port for receiving stimulation-control data to be transmitted to the configurable-logic IC for controlling stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for receiving for transmission from the hardware pod response data which the configurable-logic IC receives from the digital logic circuit in response to stimulation thereof during the stimulation-response cycle;

whereby the digital-logic simulation process may transmit stimulation-control data through the server process to the hardware pod for controlling stimulation of the digital logic circuit by the stimulus/response cells during the stimulation-response cycle, and whereby the digital-logic simulation process may receive from the hardware pod through the server process response data from stimulus/response cells of the configurable-logic IC that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

16. The hardware pod of claim 15 wherein logic-configuration data, upon being loaded into the configurable-logic IC of the hardware pod, also establishes within the configurable-logic IC, in addition to the plurality of stimulus/response cells:

a state machine for controlling the operation of the configurable-logic IC in providing stimulus signals to the digital logic circuit and in receiving responses from the digital logic circuit; and

a timing generator controlled by the state machine which establishes time intervals within the stimulation-response cycle during which individual stimulus/response cells either provides a stimulus signal to the digital logic circuit and/or receive a response from the digital logic circuit.

17. The hardware pod of claim 15 wherein the stimulus/response cells form a bit-slice architecture in which stimulus/response cells are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

18. The hardware pod of claim 15 wherein the stimulus/response cells are divided into a plurality of separate stimulus/response-cell groups, the stimulus/response cells of each separate stimulus/response-cell group forming a bit-slice architecture in which stimulus/response cells of the stimulus/response-cell group are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycle, and for uploading from the configurable-logic IC response data of a bit-slice data stream that reports the response of the digital logic circuit to stimulation during the stimulation-response cycle.

19. The hardware pod of claim 18 wherein there are four (4) separate stimulus/response-cell groups.

20. The hardware pod of claim 15 wherein the hardware pod further includes:

a RAM for storing stimulation-control data for a sequence of successive stimulation-response cycles including stimulation-control data for an initial stimulation-response cycle and stimulation-control data for a final stimulation-response cycle; and

means for selecting stimulation-control data for successive stimulation-response cycles from the RAM beginning with the initial stimulation-response cycle and ending with the final stimulation-response cycle, and for transmitting each successive stimulation-control data to the configurable-logic IC for providing the digital logic circuit with a sequence of stimulus signals, the hardware pod transmitting response data for the final stimulation-response cycle in the sequence of stimulus signals to the server process for re-transmission to the digital-logic simulation process.

21. A method for swiftly determining configuration data to be used for configuring a configurable-logic IC for performing specified digital logic functions, the configurable-logic IC including an array of configurable-logic cells that may be logically interconnected by the configuration data to perform specific digital logic functions, the method comprising the steps of:

determining, for a plurality of logic-function cells to be established within the configurable-logic IC, a digital logic function to be performed by each such logic-function cell;

retrieving from a configurable-logic cell-library, which stores configuration data that specifies various different types of individual logic-function cells, configuration data for each logic-function cell in the plurality of logic-function cells, the configuration data retrieved for each logic-function cell specifying a pre-established interconnection of several configurable-logic cells included in the configurable-logic IC which, upon loading of such configuration data into a configurable-logic IC, establishes by interconnecting several configurable-logic cells a digital logic circuit within the configurable-logic IC that performs the digital logic functions specified for that logic-function cell; and

determining the configuration data to be used for configuring a configurable-logic IC merely by assigning to specific locations throughout the configurable-logic IC the configuration data retrieved from the configurable-logic cell-library for each of the logic-function cells.

22. The method of claim 21 wherein assignment of configuration data for a pair of logic-function cells to specific locations within the configurable-logic IC includes merely juxtaposing configuration data for that pair of logic-function cells, the configuration data for the pair of logic-function cells so juxtaposed also establishing a signal path for exchanging a data signal between the pair of juxtaposed logic-function cells.

23. The method of claim 22 wherein the signal path for exchanging the data signal between the juxtaposed pair of logic-function cells passes completely across the pair of juxtaposed logic-function cells whereby the juxtaposed logic-function cells establish a signal path for transmitting a data signal through both juxtaposed logic-function cells to a third logic-function cell that may be juxtaposed with one of the two logic-function cells in the pair of logic-function cells.

24. The method of claim 22 wherein the signal path for exchanging the data signal between the juxtaposed pair of logic-function cells connects the pair of logic-function cells into a shift-register.

25. The method of claim 21 wherein the configuration data to be used for configuring a configurable-logic IC also includes configuration data that establishes within the configurable-logic IC:

a timing-signal bus, the configuration data for the logic-function cells also specifying a connection of each logic-function cell to the timing-signal bus; and

a timing generator that connects to the timing-signal bus and operation of which establishes time intervals that are transmitted over the timing-signal bus to the logic-function cell connected thereto for controlling operation of such individual logic-function cells.

26. The method of claim 25 wherein the configuration data to be used for configuring a configurable-logic IC also includes configuration data that establishes a state machine within the configurable-logic IC for controlling operation of the timing generator.

27. A faster-performance digital logic simulation/emulation system comprising:

stimulation-control data that specifies stimulation-response-cycle data to be to be applied to a digital logic circuit during stimulation-response cycles;

a hardware pod that;

is adapted for receiving the stimulation-response-cycle data, and for being coupled to the digital logic circuit;

includes a configurable-logic IC which is arranged to include a plurality of stimulus/response cells for providing stimulus signals to the digital logic circuit during the stimulation-response cycles, and for receiving responses from the digital logic circuit during the stimulation-response cycles; and

further includes a communication port for receiving stimulation-response-cycle data to be transmitted to the configurable-logic IC for controlling stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycles; and

a server process, coupled to said hardware pod for supplying stimulation-response-cycle data to said hardware pod, whereby stimulation-response-cycle data supplied by said server process to said hardware pod controls stimulation of the digital logic circuit by the stimulus/response cells during the stimulation-response cycles.

28. The digital logic simulation/emulation system of claim 27 further comprising a logic-configuration library which stores a configuration-data file that contains logic-configuration data which, upon being loaded into the configurable-logic IC of said hardware pod, establishes the plurality of stimulus/response cells in said configurable-logic IC, said logic-configuration library being coupled to said server process whereby said server process may retrieve the configuration-data file from said logic-configuration library and transmit the logic-configuration data to said hardware pod for configuring the configurable-logic IC.

29. The digital logic simulation/emulation system of claim 28 wherein the logic-configuration data, upon being loaded into the configurable-logic IC of said hardware pod, also establishes within the configurable-logic IC, in addition to the plurality of stimulus/response cells:

a state machine for controlling the operation of the configurable-logic IC in providing stimulus signals to the digital logic circuit and in receiving responses from the digital logic circuit; and

a timing generator controlled by the state machine which establishes time intervals within the stimulation-response cycles during which individual stimulus/response cells either provides a stimulus signal to the digital logic circuit and/or receive responses from the digital logic circuit.

30. The digital logic simulation/emulation system of claim 28 wherein the logic-configuration data, upon being loaded into the configurable-logic IC of said hardware pod, also establishes within the configurable-logic IC, in addition to the plurality of stimulus/response cells:

a comparator digital-logic-circuit for comparing with response data included in the stimulation-response-cycle data received by the communication port the responses that the configurable-logic IC receives from the digital logic circuit.

31. The digital logic simulation/emulation system of claim 28 wherein the stimulus/response cells established upon loading the configuration-data file into the configurable-logic IC of said hardware pod form a bit-slice architecture in which stimulus/response cells are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycles.

32. The digital logic simulation/emulation system of claim 28 wherein the stimulus/response cells established upon loading the configuration-data file into the configurable-logic IC of said hardware pod are divided into a plurality of separate stimulus/response-cell groups, the stimulus/response cells of each separate stimulus/response-cell group forming a bit-slice architecture in which stimulus/response cells of the stimulus/response-cell group are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycles.

33. The digital logic simulation/emulation system of claim 32 wherein there are four (4) separate stimulus/response-cell groups.

34. The digital logic simulation/emulation system of claim 27 wherein the configurable-logic IC further includes a comparator digital-logic-circuit for comparing with response data included in the stimulation-response-cycle data received by the communication port the responses that the configurable-logic IC receives from the digital logic circuit.

35. The digital logic simulation/emulation system of claim 27 wherein the stimulus/response cells form a bit-slice architecture in which stimulus/response cells are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycles.

36. The digital logic simulation/emulation system of claim 27 wherein the stimulus/response cells are divided into a plurality of separate stimulus/response-cell groups, the stimulus/response cells of each separate stimulus/response-cell group forming a bit-slice architecture in which stimulus/response cells of the stimulus/response-cell group are coupled to each other to establish a shift-register for downloading into the configurable-logic IC stimulation-control data of a bit-slice data stream which specifies stimulation of the digital logic circuit by the configurable-logic IC during the stimulation-response cycles.

37. The digital logic simulation/emulation system of claim 36 wherein there are four (4) separate stimulus/response-cell groups.

38. The digital logic simulation/emulation system of claim 27 wherein the hardware pod further includes:

a RAM for storing stimulation-control data for a sequence of successive stimulation-response cycles including stimulation-control data for an initial stimulation-response cycle and stimulation-control data for a final stimulation-response cycle; and

means for selecting stimulation-control data for successive stimulation-response cycles from the RAM beginning with the initial stimulation-response cycle and ending with the final stimulation-response cycle, and for transmitting each successive stimulation-control data to the configurable-logic IC for providing the digital logic circuit with a sequence of stimulus signals.

39. The digital logic simulation/emulation system of claim 38 wherein the hardware pod further includes central processing unit ("CPU"), and wherein the configurable-logic IC transmits the responses received from the digital logic circuit to said CPU for comparison with response data included in the stimulation-response-cycle data received by the communication port.

40. The digital logic simulation/emulation system of claim 27 wherein a computer program executed by a digital computer provides the server process.