Patent ID: 7110239

Claim:
A circuit comprising: a polarity controller configured to detect an incorrect polarity in a polarity sensitive signal and provide inversion signal in response to said incorrect polarity; and an inversion circuit configured to invert said polarity sensitive signal in response to said inversion signal, said inversion circuit comprising: at least one receiving terminal for receiving an input signal; and at least one transmitting terminal for transmitting an output signal; wherein said inversion circuit comprises first and second transceivers coupled to said at least one receiving terminal and third and fourth transceivers coupled to said at least one transmitting terminal, said first and third transceivers being configured to provide an output representative of said input signal with said first transceiver being normally enabled and said third transceiver being normally disabled, and said second and fourth transceivers being configured to provide an output representative of said output signal with said fourth transceiver being normally enabled and said second transceiver being normally disabled, and wherein said controller is further configured to detect an incorrect connection of said input signal to said at least one transmitting terminal and provide a select signal in response to said incorrect connection, and wherein said inversion circuit is configured to exchange said receiving and transmitting terminals in response to said select signal, wherein upon detection of said input signal on said transmitting terminal said select signal disables said first and fourth transceivers and enables said second and third transceivers to exchange said receiving and transmitting terminals.