Browse Prior Art Database

METHOD FOR NONINTRUSIVE OBSERVATION OF CHIP SIMULATIONS

IP.com Disclosure Number: IPCOM000007300D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2002-Mar-13
Document File: 3 page(s) / 165K

Publishing Venue

Motorola

Related People

Lane Schaller: AUTHOR [+2]

Abstract

When designing a real-time system, it is beneh- cial to verify and characterize the system's perform- ance through simulation rather than testing proto- types of the system. The analysis required for verification, however, must be done in a manner that does not impact the simulation. In general, it is use- ful to design an observable system for verification and debugging purposes. Unfortunately, an observa- ble system may not accurately portray or efficiently implement the actual desired system. Most program- mable ICs have simulators with which soflware and hardware can be emulated. They also usually have available evaluation boards on which so&ware can be tested. This publication describes a method for observing the status of a system that does not alter the actual real-time performance of the system or software under test.

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MOTOROLA Technical Developments Volume 23 October 1994

METHOD FOR NONINTRUSIVE OBSERVATION OF CHIP SIMULATIONS

analyzes the data to verify or characterize perform- ance. First, the information necessary to perform a proper analysis for verification must be determined. Then this data must be collected during the simula- tion. The data output by the simulation can then be analyzed to verily and characterize hmctional and temporal performance.

  Determining what data is required to perform the analysis or verification is dependent on the sys- tem. It may be useful to observe the value ofa varia- ble or status register at regular intervals. It may also be useml to track the status of variables and timers when specific sections of code are executed. The order in which routines are executed can also be tracked in this manner, allowing verification and characteri- zation of system performance.

  To properly implement this method, gathering and analyzing data from the simulation must meet several requirements.

The simulation must be run on a cycle-exact sim- ulator of the processor in the system.

A section of observation (debugging) code must be executed at appropriate times, outputting per- tinent information about the simulation, This code should be considered part of the simulation. It is not required for the system to operate, only for the analysis ofthe simulation.
* The analysis of the output data must consider the format and order used by the observation code.

by Lane Schaller and Brett Lindsley

  When designing a real-time system, it is beneh- cial to verify and characterize the system's perform- ance through simulation rather than testing proto- types of the system. The analysis required for verification, however, must be done in a manner that does not impact the simulation. In general, it is use- ful to design an observable system for verification and debugging purposes. Unfortunately, an observa- ble system may not accurately portray or efficiently implement the actual desired system. Most program- mable ICs have simulators with which soflware and hardware can be emulated. They also usually have available evaluation boards on which so&ware can be tested. This publication describes a method for observing the status of a system that does not alter the actual real-time performance of the system or software under test.

  Motorola's OnCE" port provides the ability to observe the status of the processor on which the port resides. The OnCE" port is essentially a hard- ware implementation ofa real-time observation sys- tem. However, the status of the system in which the chip resides may change during the observation. Spe- cifically, clocks and peripherals still operate. Thus, the observations made would be intrusive to the testing.

  "Profilers" such as the Microsoff Source Pro- filer (see Microsoft's Source Profiler User's Guide) allow users to analyze the run-time behavior oftheir programs. These profilers only perform analysis in the manner s...