Response Delay
Embedded microcontrollers experience a finite time delay between the receipt of a hardware trigger signal and the execution of the corresponding service routine. The interrupt latency defines this time interval, which limits the real-time performance of data acquisition systems and high-speed sensor interfaces. This delay must remain below a critical threshold to prevent data loss in dynamic processes.
It represents a key performance parameter for choosing industrial processing units.
Internal Cause
Hardware register pushing and instruction execution states dictate the minimum response time of the CPU. This dependency creates jitter in the measurement loop.
Sensor Consequence
Data conversion cycles can be missed when the processing delay exceeds the sample period of the sensor. In high-frequency vibration and acoustic measurements, this timing uncertainty introduces phase noise into the digitized signal. This effect degrades the signal-to-noise ratio of the system.
Measurement Method
Digital oscilloscopes measure the response time by tracking the physical delay between the external interrupt pin and a GPIO test pin toggled inside the routine. Automated test runs execute these triggers repeatedly under varying software loads to determine the maximum delay and jitter. These timing patterns help designers tune the interrupt priority schemes to meet strict real-time guarantees.
The final timing budget must conform to the requirements of the high-speed data stream.
