TIMER PIL Profiling - PIL Timing Profiler

dsPIC30F dsPIC33F dsPIC33E dsPIC33C dsPIC33A PIC32

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TIMER PIL Profiling - PIL Timing Profiler Timer_PIL_Profiling Block Icon The MCHP_TIMER_PIL_Profiling block enables precise code execution timing measurement during Processor-in-the-Loop (PIL) simulations. It uses hardware timers to measure actual execution time of Simulink subsystems or blocks on target hardware. This block is essential for performance profiling, real-time constraint verification, and optimization of embedded code. It provides microsecond-level timing accuracy using the target’s hardware timer peripheral.

Overview

The MCHP_TIMER_PIL_Profiling block enables precise code execution timing measurement during Processor-in-the-Loop (PIL) simulations. It uses hardware timers to measure actual execution time of Simulink subsystems or blocks on target hardware.

This block is essential for performance profiling, real-time constraint verification, and optimization of embedded code. It provides microsecond-level timing accuracy using the target’s hardware timer peripheral.

When to use:

• PIL testing — Measure actual execution time on target hardware during PIL simulation
• Performance profiling — Identify slow subsystems or optimization targets
• Real-time verification — Confirm code meets timing deadlines before deployment
• Code optimization — Benchmark different algorithm implementations on target
• Worst-case timing — Measure maximum execution time for safety-critical systems

When NOT to use:

• Normal simulation — Block only active during PIL, not in standard Simulink simulation
• External Mode — External Mode provides signal monitoring (use profiling for timing only)
• Code generation only — If not running PIL tests, profiling block not needed
• Instrumentation overhead — Timer reads add overhead to measured code (small but present)
• Already optimized — If timing constraints easily met, profiling not necessary

Block Dialog

Ports

Inputs: None (profiling markers inserted automatically)

Outputs:

• ExecutionTime - Measured execution time in selected units
• OverflowFlag - Indicates timer overflow (measurement invalid)

Parameters

Timer Resource Selection

Timer Resolution

Note: The timer resolution dropdown shows available prescaler options with their corresponding resolution and maximum measurement period. Lower resolution provides longer maximum periods but less precise measurements.

Timer Information

Device Support

Examples

Example 1: Measure Subsystem Execution Time

1. Place MCHP_TIMER_PIL_Profiling block in model
2. Configure for Start/Stop mode
3. Build and run PIL simulation
4. Monitor ExecutionTime output signal

Example 2: Verify Real-Time Constraints

% MATLAB verification script
maxAllowedTime = 100; % microseconds
if ExecutionTime > maxAllowedTime
    warning('Real-time constraint violated!');
end

Implementation Details

Profiling Mechanism

• Start Marker: Captures timer value before code execution
• Code Execution: Target code runs normally
• Stop Marker: Captures timer value after execution
• Calculation: Elapsed time = (Stop - Start) / Timer Frequency

Timer Resolution by Family

• dsPIC @ 60MHz Fcy: 16.67ns per tick (1:1 prescaler)
• PIC32 @ 200MHz: 5ns per CPU cycle
• SAMx7 @ 300MHz: 3.33ns per CPU cycle

Related Blocks

• MCHP_TIMER_Config - Timer resource configuration
• PIL Testing - PIL testing workflow
• External Mode - External mode debugging