Fast and compact circuit for bus inversion

A system comprising:

• a bus master coupled to a bus slave via a bus, said bus master transmitting bits to the slave over the bus, said bus master comprising a bus inversion system comprising:
• an advantage function circuit, said advantage function circuit inputting bits to be transmitted over the bus, said advantage function circuit calculating an advantage of inversion and an advantage of non-inversion for each input bit and calculating an advantage of inversion and an advantage of non-inversion for an inversion bit to be transmitted over the bus, said advantage function circuit having a plurality of first and second outputs, each first output corresponding to one of the advantage of inversion of a respective bit to be transmitted over the bus or the advantage of inversion for the inversion bit, each second output corresponding to one of the advantage of non-inversion of a respective bit to be transmitted over the bus or the advantage of non-inversion for the inversion bit, said advantage function circuit implementing an advantage function that uses said advantages to achieve preferred power consumption when transmitting the bits to be transmitted over the bus;
• a majority voter circuit coupled to the plurality of first and second outputs, said voter circuit determining whether the bits to be transmitted over the bus should be inverted before being transmitted by substantially simultaneously comparing first and second currents within branches of the majority voter circuit based on the first and second outputs, said majority voter circuit comprising a third output corresponding to a summation of said first outputs and a fourth output corresponding to a summation of said second outputs;
• and
• an inversion logic circuit coupled to the third and fourth outputs of the majority voter circuit.