Patent ID: 7208981
Filing Date: 2007-04-24
Classification: H04L

Abstract:
1. A apparatus including an integrated circuit with differential signal generator circuitry and built-in test circuitry therefor, comprising: a plurality of reference electrodes via which are received first upper and lower reference voltages and second upper and lower reference voltages, wherein test signal generator circuitry via which is provided a plurality of binary signals with respective successions of opposing signal states; differential signal generator circuitry coupled to said test signal generator circuitry and responsive to said plurality of binary signals by providing a plurality of differential signals having respective magnitudes related to said respective successions of opposing binary signal states; and signal comparison circuitry coupled to said plurality of reference electrodes and said differential signal generator circuitry, and responsive to said and second upper and lower reference signals and said plurality of differential signals by providing a plurality of test signals with respective test signal states indicative of whether respective ones of said differential signal magnitudes are within a range defined as being less than said first difference magnitude and greater than said second difference magnitude.