A system and an integrated circuit device therefor. The integrated circuit device comprises output driver circuitry to output data onto a first external signal line. The output driver circuitry outputs a first portion of data in response to a rising edge transition of a first external clock signal. The output driver circuitry outputs a second portion of data in response to a falling edge transition of the first external clock signal. The integrated circuit device may further include input receiver circuitry to sample data from a second external signal line. The input receiver circuitry samples a first portion of data in response to a rising edge transition of a second external clock signal. The input receiver circuitry samples a second portion of data in response to a falling edge transition of the second external clock signal.