Data capture is an on-board debug feature of the device. When a value in the Capture Data Address register matches an SFR register address, a trigger and data capture occurs. You cannot access data capture directly; you must select an application that uses data capture, such as the DMCI plug-in.
Runtime Watches are selected symbols in a Watches window that change as the program runs. You can select a symbol to be runtime in a Watches window. See MPLAB® X IDE documentation for details.
8- and 16-Bit Devices
Not all 8- and 16-bit devices support data capture and/or runtime watches. For a list of supported features by device, see Hardware Tool Debug Feature Support by Device.
When watching symbols, an 8-bit PIC device can only watch 8-bit variables and a 16-bit PIC device can only watch 16-bit variables.
For 8- and 16-bit devices, data captures, runtime watches, and hardware breakpoints use the same registers/resources. For example, if you use a data capture resource for a symbol, you will not be able to use a hardware breakpoint or runtime watch resource for that symbol.
For data captures and runtime watches at speeds higher than 15 MIPS, the Performance Pak (AC244002) may be needed. The actual speed may vary depending on layout, noise, and similar considerations.
32-Bit Devices
Not all 32-bit devices support data capture and/or runtime watches. For a list of supported features by device, see Hardware Tool Debug Feature Support by Device.
For PIC32 devices, hardware breakpoints do not use data capture or runtime watch resources. However, data captures and runtime watches do use the same resources. Therefore, if you use a data capture resource for a symbol, you will not be able to use a runtime watch resource for that symbol, and vice versa.
The Performance Pak is not required for debugging at maximum speeds as the capture clock speed is independent of the target system clock.