When a ring oscillator is continuously sampled without accumulating enough jitter, the produced bitstream shows periodic behavior. Autocorrelation count test is able to detect this behavior. It uses time-division multiplexing and even single ring oscillator case is supported. Window size of W = 128 samples is used with cut-off values defined as in AUTOCORRTESTCUTOFF registers. Specific delay checks (or all checks) can be disabled via CONTROL.DISAUTOCORRTESTS.