Debug GPIO channels are timestamped digital signal lines connecting the
target application to a host computer visualization application. They are typically used
to plot the occurrence of low-frequency events on a time-axis – for example, when
certain application state transitions occur.
The figure below shows the monitoring of the digital state of a mechanical
switch connected to a debug GPIO in MPLAB Data Visualizer.
Figure 1. Monitoring Debug GPIO with
MPLAB® Data Visualizer
Debug GPIO channels are timestamped, so the resolution of DGI GPIO events is
determined by the resolution of the DGI timestamp module.
Important: Although bursts
of higher-frequency signals can be captured, the useful frequency range of signals
for which debug GPIO can be used is up to about 2 kHz. Attempting to capture signals
above this frequency will result in data saturation and overflow, which may cause
the DGI session to be aborted.