Error measurement circuit

摘要

The invention provides a circuit and method for performing test procedures on a data storage and recovery system for a magnetic storage unit. Error sample values from a read operator in a data storage and recovery system are applied to a first and a second process path to generate output signals. A source of level samples of a logical data level is also provided. The first process path generates an output signal comprising a square of each error value sample. The second process path compares the error value samples and a compare level and generates an output signal comprising a result of each comparison. The output signal of the first process path, the second process path, or the level samples is selected and is associated with a data type. In response to a coincidence of a data type associated with a selected signal with a desired data type, the selected signal is gated and then accumulated. The window during which the selected signal is accumulated may vary. The accumulated value is used as an input variable to a selected test to determine the accuracy of the data storage and recovery system.