A resistance calibration code generating apparatus includes a code calibration unit configured to calibrate and output code values of a resistance calibration code during predetermined cycles of a calibration clock, which are determined by a code calibration time control command, and a calibration clock generating unit configured to output the calibration clock using a code calibration command. The tasks may include at least one task that is to be performed by all worker devices, and may include at least one task that is to be performed by one worker device. Aspects of the invention provide the advantage of effectively removing noise from biosignals without distorting the waveforms of the biosignals.