Patent ID: 7509568

Claim:
A method in a data processing system for identifying types of errors that occur in a communications device under test and that are indicated by an error checker, said method comprising: during each one of a plurality of contiguous time periods: identifying each presence of an error bit in an error signal output from said error data checker, said error bit indicating only that a mismatch occurred between an input signal input into said device and an output signal output from said device, said error bit being generated in response to an error in said device, said error bit including no information about a type of said error; and determining said type of said error by determining a number of occurrences of said error bit during said one of said plurality of contiguous time periods; each one of said plurality of contiguous time periods being equal to a particular number of clock cycles of a system clock; in response to determining that said number of occurrences is only one occurrence of said error bit, determining that said type of said error is an isolated type of error; in response to determining that said number of occurrences of said error bit is greater than one but less than a threshold, determining that said type of said error is a burst type of error; in response to determining that said number of occurrences of said error bit is greater than or equal to said threshold, determining that said type of said error is a long term type of error; receiving said error signal output within an error identification circuit; counting, by a first counter in said error identification circuit, each occurrence of said error bit during said one of said plurality of contiguous time periods; counting, by a second counter in said error identification circuit, a number of elapsed clock cycles that have elapsed since a start of a last one of said plurality of contiguous time periods; and; in response to said number of elapsed clock cycles being equal to said particular number of clock cycles, identifying a start of a next one of said plurality of contiguous time periods.