Error analyzer for data communicated by bus protocol

In a system for detecting errors in data handled in biphase format on a bus in accordance with a certain bus protocol, the improvement comprising:

• positive and negative analyzer means, respectively responsive to the separately measured time durations of positive and negative excursions of said data, for determining the occurrence of a sync signal in said data characterized by the consecutive occurrence of excursions of opposite polarity each of a first certain time duration, said analyzer means also detecting a bus inactive condition and providing a signal indicative thereof,
• bit time counting means for counting the total number of bits present in said data, or alternatively for counting bit timing clock pulses corresponding to the expected occurrence rate of data bits on said bus, and
• means for ascertaining the accumulated count upon next subsequent detection by said positive and negative analyzer means of a sync signal or of a signal indicative of a bus inactive condition, and for determining the numerical relationship between said count and the expected number of data bits transmitted in each word in accordance with said certain bus protocol, such numerical relationship indicating a corresponding number of bits error.

In a system for detecting errors in data handled in biphase format on a bus in accordance with a certain bus protocol, the improvement comprising:

• positive and negative analyzer means for measuring the respective time durations of positive and negative excursions of said biphase data on said bus, and for determining in response thereto the occurrence of consecutive data excursions of opposite polarity for time durations indicative of a synchronization signal, and for thereafter determining the occurrence of positive or negative excursions of said date the time durations of which do not correspond to an acceptable bit excursion duration, such condition being indicative of a transition error in said data, said analyzer means also detecting a bus inactive condition and providing a signal indicative thereof, and
• means for providing a corresponding error indication upon detection by said analyzer means of the next subsequent sync signal or of a signal indicative of a bus inactive condition.