A symbol error detector can be configured to detect symbol errors of GFSK modulated portions of a Bluetooth packet without relying solely on a CRC error detection mechanism. The first marking device is incorporated in the body and in communication with the first chamber to access the marking substance contained by the inner surface. A biasing element is adapted to act upon the mirror element when the mirror element is encapsulated in the case to apply a force against the mirror element in a first direction. The stage of the code-load failure is identified. The units are arranged such that the fluid is forced to flow between the units in a serpentine path. The programmable logic device may include a number of super logic cells, each of which includes a plurality of logic cells.