Methods and apparatuses for time annotated transaction level modeling

• US 9,087,036 B1
• Filed: 08/11/2005
• Issued: 07/21/2015
• Est. Priority Date: 08/12/2004
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Sonics Incorporated (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Chou, Chien-Chun, Kamas, Alan
• Primary Examiner(s): Chad, Aniss
• Application Number:
  US11/203,554
• Time in Patent Office: 3,631 Days
• Field of Search: 703 23- 25
• US Class Current: 1/1
• CPC Class Codes: G06F 11/261 by simulating additional hardware, e.g. fault simulation
• CPC Class Codes: G06F 12/0607 Interleaved addressing
• CPC Class Codes: G06F 30/3312 Timing analysis
• CPC Class Codes: H04L 41/145 involving simulating, designing, planning or modelling of a network

Abstract

A method and apparatus for transaction level modeling where communications occur between modules in the system that contain time annotations is described. An apparatus includes an initiator module, a target module, and a communications channel with each being modeled as an executable behavioral model. The communications channel transports burst information between the initiator module and the target module. The communications channel has a timing variable function to store timing variables and derive timing information associated with each individual transfer within a burst transaction during a simulation.

Claims

1. A non-transitory machine-readable storage medium having instructions stored thereon, which when executed by a machine, are configured to cause the machine to generate an apparatus, comprising:

an initiator module modeled as a first executable behavioral model;

a target module modeled as a second executable behavioral model, where information regarding a burst transaction is communicated between the initiator module and the target module of a System on a Chip through a communications channel, where the burst transaction consists of two or more individual transfers and the communications channel is separate and distinct from both the initiator module and the target module; and

one or more timing function routines configured to obtain timing variables for the burst transaction that uses a communications protocol that includes distinct fields of a command field and a timing field for the burst transaction communicated between the initiator module and the target module, where the timing field includes

     1) timing variables, or

     2) derived timing information based on the timing variables, where either the initiator module or the target module use the one or more timing function routines to determine the timing information associated with each of the two or more individual transfers within the burst transaction during a simulation, by either

     1) making a direct function call to the communications channel that the burst transaction passes through to retrieve information about the burst transaction including its timing information or

     2) basing the timing information on the timing variables or the derived timing information contained in the timing field for the burst transaction, and then using the one or more timing function routines to derive timing information associated with each individual transfer within the burst transaction during the simulation, where the derived timing information associated with each individual transfer within the burst transaction is correlatable to give an accurate correlation to a clock cycle operation of the System on a Chip during the simulation.

2. The non-transitory machine-readable storage medium of claim 1, where the first executable behavioral model of the initiator module is also configured to make a second function call to retrieve information about the burst transaction including its timing information and use the one or more timing function routines to derive timing information associated with each individual transfer within the burst transaction during the simulation, and where data and commands are sent from one module to another module through function calls.

3. The non-transitory machine-readable storage medium of claim 2, where the first executable behavioral model of the initiator module uses a first timing function routine of the one or more timing function routines that is configured to use time annotated modeling to make the derived timing information associated with each individual transfer within a burst transaction cycle accurate to the clock cycle operation of the System on a Chip used during the simulation.

4. The non-transitory machine-readable storage medium of claim 1, wherein the timing information associated with a first individual transfer is derived separately from the timing information associated with a second individual transfer and where both the derived timing information associated with the first individual transfer within the burst transaction and the derived timing information associated with the second individual transfer within the burst transaction are correlatable to give the accurate correlation to the clock cycle operation of the System on the Chip during the simulation.

5. The non-transitory machine-readable storage medium of claim 4, where the burst transaction also has the command field and a data field to store the derived timing information associated with the burst transaction.

6. The non-transitory machine-readable storage medium of claim 1, where a model of the communications channel is configured to transport the burst transaction and estimate timing points for each request and response transfer associated with the burst transaction between the initiator module and the target module in the System on a Chip based on the burst transaction having one or more fields containing an accurate time annotation for the two or more individual transfers in the burst transaction.

7. The non-transitory machine-readable storage medium of claim 1, further comprising:

the communications channel is modeled as a third executable behavioral model that has one or more storage locations to store the timing variables associated with the burst transaction being communicated between the initiator module and the target module, where the target module as the second executable behavioral model is configured to make the direct function call to the communications channel to obtain the timing variables associated with the burst transaction.

8. The non-transitory machine-readable storage medium of claim 1, wherein the first executable behavioral model of the initiator module uses a routine to calculate timing points for a first transfer within the burst transaction based on the timing variables stored and timing information derived in a first timing variable function routine of the model of the communications channel.

9. The non-transitory machine-readable storage medium of claim 1, wherein the target module as the second executable behavioral model calculates timing points for a first transfer received within the burst transaction based on the timing variables stored and the timing information derived in the one or more timing variable functions of a communications channel model.

10. The non-transitory machine-readable storage medium of claim 1, wherein the first executable behavioral model of the initiator module is a transaction level model written in a SystemC language.

11. The non-transitory machine-readable storage medium of claim 6, wherein the model of the communications channel is configured as a time annotated Open Core Protocol (OCP) Transaction Level 2 (TL2) channel.

12. A method for modeling operation of a System on a Chip to provide time annotated transaction level modeling, comprising:

simulating transporting of burst transaction information including a plurality of transfers from a first model of an initiator module through a communications channel to a second model of a target module in the System on the Chip, wherein the communications channel is separate and distinct from both the initiator module and the target module;

maintaining a first set of timing variables associated with the initiator module;

using a communications protocol that includes distinct fields of a command field and a timing field for the burst transaction information communicated between the initiator module and the target module, where the timing field includes

     1) timing variables, or

     2) derived timing information based on the timing variables;

maintaining a second set of timing variables associated with the target module using one or more timing function routines to

     1) obtain the first set and the second set of timing variables for the burst transaction information communicated between the initiator module and the target module,

     2) derive timing information associated with a first individual transfer within the burst transaction during the simulation, and

     3) derive timing information associated with a second individual transfer within the burst transaction during the simulation; and

where the second model of the target module is configured to make a function call to retrieve information about the burst transaction including its timing information and is configured to use the one or more timing function routines to derive the timing information associated with the first individual transfer and the second individual transfer within the burst transaction during the simulation, where the derived timing information associated with each individual transfer within the burst transaction is correlatable to give an accurate correlation to a clock cycle operation of the System on the Chip during the simulation.

13. The method for modeling operation of the System on the Chip of claim 12, where the first model of the initiator module is configured to make the function call to retrieve information about the burst transaction including its timing information and use the one or more timing function routines to derive the timing information associated with each individual transfer within the burst transaction during the simulation, and where data and commands are sent from one module to another module through function calls.

14. The method for modeling operation of the System on the Chip of claim 13, where the first model of the initiator module uses a first timing function routine of the one or more timing function routines that is configured to use the time annotated transaction level modeling to make the timing information associated with each individual transfer within a burst transaction cycle accurate to the clock cycle operation of the System on the Chip used during the simulation, wherein the timing information associated with the first individual transfer is derived separately from the timing information associated with the second individual transfer.

15. The method for modeling operation of the System on the Chip of claim 12, where the burst transaction has a timing field and a burst information field to store timing information associated with the burst transaction.

16. The method for modeling operation of the System on the Chip of claim 12, where the burst transaction also has a command field and a data field to store timing information associated with the burst transaction.

17. The method for modeling operation of the System on the Chip of claim 12, where a model of the communications channel is configured to transport the burst transaction and estimate timing points for each request and response transfer associated with the burst transaction between the initiator module and the target module in the System on the Chip based on the burst transaction having one or more fields containing an accurate time annotation for transfers in the burst transaction.

18. The method for modeling operation of the System on the Chip of claim 12, further comprising:

simulating the communications channel modeled as an executable behavioral model that has one or more storage locations to store the first set and the second set of timing variables associated with the burst transaction being communicated between the initiator module and the target module, where the second model of the target module is configured to make the function call to the communications channel to obtain the second set of the timing variables associated with the burst transaction.

19. A computing system, comprising:

a processor component cooperating with a non-transitory machine readable storage medium, where the processor component is configured to execute instructions in a simulation to simulate

an initiator module modeled as a first behavioral model that generates a first set of timing variables for a burst transaction;

a target module modeled as a second behavioral model that generates a second set of timing variables for each transfer in the burst transaction, where the initiator module and target module are part of a System on a Chip, where the System on the Chip is configured to use a communications protocol that includes distinct fields of a command field and a timing field for communication of the burst transaction information from the initiator module through a communications channel to the target module, where the burst transaction includes three or more transfers within the burst transaction and the communications channel is separate and distinct from both the initiator module and the target module; and

one or more timing function routines to derive burst information for the three or more transfers in the burst transaction so that timing information for each transfer is cycle accurate to a clock cycle operation of the System on the Chip during the simulation, where the one or more timing function routines are configured to obtain timing variables from either the first or second set of timing variables for the burst transaction that use the communications protocol including its distinct fields of the command field and the timing field for the burst transaction, where the timing field includes

     1) the timing variables from either the first or second set of timing variables for the burst transaction, or

     2) derived timing information based on the timing variables, where the timing function routines obtain the timing variables from either the first or second set of timing variables for the burst transaction depending upon whether the target module or the initiator module generated the burst transaction, where either the initiator module or the target module use the one or more timing function routines to determine the timing information associated with each of the two or more individual transfers within the burst transaction during a simulation, by either

     1) making a direct function call to the communications channel that the burst transaction passes through to retrieve information about the burst transaction including its timing information or

     2) basing the timing information on the timing variables from either the first or second set of timing variables for the burst transaction or the derived timing information contained in the timing field for the burst transaction, and then using the one or more timing function routines to derive timing information associated with each individual transfer within the burst transaction during the simulation.

20. The computing system of claim 19, further comprising:

a channel module to store the first and second set of timing variables; and

a processing module configured to calculate when each transfer in the burst transaction started on the channel module and a latency for each transfer crossing the channel module based on the first and second set of timing variables.