Abstract: A test signal to be supplied to a driver section when the driver section is subjected to an operation test is generated by a test circuit. In the test circuit, the test signal can be generated by a burn-in control circuit in accordance with a clock signal TESTCK supplied from an outside source.

Abstract: A frequency detector includes a slicer to receive and slice a phase error against a compare threshold value. The slicer generates a symbol based on the phase error sliced against the compare threshold value. A symbol counter is provided to increment a symbol count if the symbol generated is the same as a last symbol. A logic circuit compares the symbol count with a symbol count limit if the symbol is different from the last symbol. The logic circuit increments a high counter and clears a low counter if the symbol count is less than the symbol count limit. The logic circuit increments the low counter and clears the high counter if the symbol count is greater than the symbol count limit. A combinational logic circuit is provided to generate a high frequency jitter true signal or a high frequency jitter false signal based on at least one of the symbol count, the high counter, and the low counter.