| 摘要 |
PURPOSE: To correct an error by generating the timing signal and strobe signal, generating pulses sampled by the latter, sampling the pulses with the strobe signal via a comparator, and detecting the jitters of the strobe signal from the compared result. CONSTITUTION: A timing generator 10 feeds the timing signal TT to a format controller 12 and feeds the strobe signal TS having the same frequency and a prescribed phase difference to a pattern comparator 13. At the time of an operation test, a pattern generator 11 feeds the desired test pattern TP synchronized with the timing signal TT by the format controller 12 to a driver 15 and feeds the expected value TP' to the comparator 13. At the time of the check mode, the pattern TP and the expected value TP' become all 1 or O, a pulse generator 17 is connected, and pulses are sampled by the signal TS. An arithmetic unit 19 grasps jitters from the wave-form of the strobe signal TS and instructs the timing generator 10 to adjust the timing error so that the timing signal TT and the strobe signal TS keep the normal phase difference. |
