Hardware reset reason

摘要

Some microprocessors and microcontrollers have a bi-directional reset pin. In such devices, output signals on the reset pin are decoded by reset reason decode logic circuitry. The output of the reset reason decode logic can be provided to another device or processor, which generates a readily recognizable output signal indicative of a reason why the processor reset. Output signals that can indicate why a processor was reset can include a high or low state of different durations, serial bit streams or a number of pulses, each of which correspond to and therefore identify a reason why the processor was reset.

主权项

1. A processor comprising:
a plurality of busses, each bus comprising a corresponding plurality of conductors, each bus providing corresponding connections between the processor and addressable circuits; a reset decoding device comprising combinational logic circuits coupled to the conductors of each bus, the combinational logic circuits being configured to:
evaluate binary-valued signals on the plurality of busses, which identify an event that caused the processor to reset itself; andoutput a signal on a first processor pin, the signal output on the first processor pin identifying the event causing the processor to reset itself, wherein the signal on the first processor pin comprises a binary valued signal capable of having a plurality of different time durations, the time duration of the binary-valued signal corresponding to an event that caused the processor to reset itself.