VDB provides several functions to support debugging. In order to be flexible and non-intrusive, it is designed to be self-contained so that the developer does not need to change the wiring configuration. Another utility program -- VDBTerm -- serves as a terminal that displays the debug messages.

VDB (NO wiring needed)

Tutorial -- Examples with step by step instructions. Illustrates how to: print out debug messages to UART, use "assert" to reliably verify/examine the program's execution status, read/write the in-chip 4KB EEPROM, and stack boundary check.

Source code -- vdbavr.h, vdbavr.inc, VDBTerm (source)

* Multiple modules can all include "vdbavr.inc" without incurring conflicts.

* Define "NO_COMM" macro in vdbavr.inc if you try VDB with Blink! Generally, If the application does NOT use the GenericComm/GenericCommPromiscurious components, and there is NO handler for UART interrupts, the macro NO_COMM must be defined before including "vdbavr.inc". When this macro is defined, vdb handles the UART interrupt. Note that, though any multiple modules can include "vdbavr.inc", only one can have NO_COMM defined

* Caveats: Like most of the debugging tools, VDB changes the timing of the execution of the program. Also, if the application uses UART, print() should be used with caution. Otherwise, there may be a conflict on the UART operations.

Bug reports:

Lin Gu <lingu AT virginia DOT edu>

Liqian Luo <ll4p AT virginia DOT edu>